Grammar

The error is in part (C). This is a Type 3 conditional sentence (unreal past). When the if-clause uses 'Had he invited' (past perfect), the main clause should use 'would have + past participle' (would have attended), not 'would attend'. The correct sentence should be 'Had he invited me, I would have attended the function.'

The error is in part (A). This is a Type 3 conditional sentence where the result clause uses 'would have + past participle'. Therefore, the if-clause should use past perfect 'had come' instead of simple past 'came'. The correct sentence is 'If he had come to me, I would have given him a pen.'

The error is in part (C). In a question beginning with 'what', the auxiliary verb 'will' should come before the subject 'you', not after. The correct question word order is 'what will you do?', not 'what you will do'. This is a basic subject-verb inversion rule for questions.

The error is in part (C). The verb phrase 'would have gave' is grammatically incorrect. After 'would have', we must use the past participle form 'given', not the past tense form 'gave'. The correct phrase is 'would have given him the address'. This is a common error confusing past tense and past participle forms.

The error is in part (A). In conditional sentences (Type 1), the if-clause should use simple present tense, not 'will'. The correct structure is 'If he works hard, he will get promotion'. Using 'will' in both the if-clause and main clause is redundant and grammatically incorrect. The simple present 'works' is required in the if-clause.

Unless is used instead of if + not in conditional sentences of all types. It will use unless with present tense and double future tense should be avoided. Correct phrase is .... Unless he asks me, I shall not help him.

The error is in part (A). This is a Type 2 conditional sentence describing a hypothetical present situation. The if-clause should use simple past 'had', not present 'have'. The correct form is 'If I had an umbrella, I would give it to her' (Type 2) or if referring to a past situation, 'If I had had an umbrella, I would have given it to her' (Type 3). Present 'have' is grammatically incorrect.

The error is in part (B). The phrase 'will have lend' contains two errors: 'will have' is incorrect for Type 2 conditional (should be 'would'), and 'lend' is the base form where past participle 'lent' is needed. The correct sentence should be 'If I had a briefcase, I would lend it to her' (Type 2). The combination 'will have lend' is grammatically incoherent.

The error is in part (A). In Type 2 conditional sentences (hypothetical present/unreal), the verb 'to be' in the if-clause must be 'were' for all subjects, including first person 'I', not 'was'. The correct form is 'If I were you, I would dismiss him from the job'. This is called the subjunctive mood, and 'was' is never correct in formal conditional sentences.

The error is in part (C). In Type 3 conditional sentences (unreal past), the main clause should use 'would have + past participle', not 'can' which is present tense. The correct sentence is 'Had he tried again, he would have passed the examination' or 'could have passed'. Using present modal 'can' with a past conditional is grammatically incorrect.

The correct answer is 'until'. The sentence 'I will stay here until you come' means the staying action continues up to the point when you arrive. 'Unless' means 'if not' which would reverse the meaning. 'If' introduces a condition, not a time boundary. 'Incase' (properly 'in case') means 'in the event that', which is inappropriate here.

Correct Answer: Unless

Unless you work hard, you can't secure first position.

This is a second conditional sentence expressing a hypothetical situation. For all subjects (including I, he, she), we use 'were' in the if-clause of second conditional sentences. The main clause uses 'would + base verb'.

The error is in part (B). The if-clause uses present continuous ('are looking'), which indicates a real or ongoing situation. This should be followed by 'will find' (first conditional), not 'would find'. The tenses don't match.

The error is in part (A). The sentence uses 'Unless' incorrectly with an imperative structure. It should be 'Don't wait for him unless he comes back' or rephrased entirely. Starting with 'Unless' before 'wait for him' creates a disconnected conditional.

This is a second conditional sentence expressing a hypothetical situation. The if-clause uses 'were' (subjunctive for hypothetical), and the main clause uses 'would + base verb' ('would dismiss'). This structure shows an imaginary scenario.

This is a zero conditional sentence expressing a general scientific truth or universal fact. Zero conditionals use present simple in both clauses: 'If you boil water, it turns into vapours'. This describes what always happens under these conditions.

This is a first conditional sentence predicting a likely future result. The if-clause uses present simple ('tries'), and the main clause uses 'will + base verb' ('will pass'). This structure shows a real possibility of success.

 'Until' is a condition of time and is unsuitable to the context. We need 'unless' here.

Sentence (A) is incorrect because it uses 'will' in the if-clause ('If the fog will get thicker'), which is grammatically wrong. We never put 'will' inside the if-clause. Sentence (B) is correct: 'If the fog gets thicker, the plane will be late' follows proper first conditional structure.

Sentence (A) is correct: 'If he runs fast, he will reach in time' follows proper first conditional structure with present simple in the if-clause and 'will' in the main clause. Sentence (B) is incorrect because it uses 'will' in the if-clause ('If he will run'), which is never grammatically correct.

This is a third conditional sentence expressing regret about a past situation that didn't happen. The structure is: If + past perfect ('had invited'), would have + past participle ('would have attended'). This shows what would have been different under other past circumstances.

Sentence (A) is incorrect because after 'stop', we need the gerund form ('raining') not the infinitive ('rain'). The verb 'stop' is followed by -ing when meaning to cease an action. Sentence (B) is correct: 'If it stops raining, we can go to the terrace'.

Both sentences are grammatically correct. Sentence A correctly uses 'may' to indicate permission, and sentence B correctly uses 'can' to indicate ability. Both are appropriate responses to the condition of having a confirmed ticket.

Sentence A is correct because it uses proper first conditional structure: 'If you want' (present) + 'eat' (imperative). Sentence B is incorrect because it mixes 'wanted' (past) with 'eat' (imperative) - it should be 'If you want to lose weight, eat fewer potatoes' or 'If you wanted to lose weight, you would eat fewer potatoes' (second conditional).

Sentence A is correct because it properly uses first conditional: 'If it rains' (present) + 'he will not come' (future). Sentence B is incorrect because it mixes second conditional 'If it rained' with first conditional result 'he will not come' - it should be 'If it rained, he would not come' (second conditional) or 'If it rains, he will not come' (first conditional).

Part (A) 'you will heat ice' contains an error. In conditional sentences describing scientific facts or general truths, the if-clause should use present simple, not 'will'. The correct form is 'If you heat ice, it will turn to water'. The use of 'will' in the if-clause is grammatically incorrect.

Sentence A is incorrect because 'if he will run fast' uses 'will' in the if-clause, which is grammatically wrong. Sentence B is correct because 'if he runs fast' properly uses present simple in the if-clause with 'will' in the main clause (first conditional pattern).

Sentence A is correct because it properly uses present simple 'If you boil water' to describe a general scientific fact, with 'it turns' also in present simple. Sentence B is incorrect because it incorrectly places 'will' in the if-clause - 'If you will boil water' is grammatically wrong in conditional structures.

Sentence A is incorrect because it uses 'whether' incorrectly in a conditional request structure - 'whether you tell her' makes no sense grammatically. Sentence B is correct because 'could you tell her to ring me' is a proper polite conditional request using modal 'could' to make a request.

Sentence A is correct because it properly uses present simple 'if the fog gets thicker' in the if-clause. Sentence B is incorrect because it uses 'will' in the if-clause 'if the fog will get thicker' - in conditional sentences, 'will' should never appear in the if-clause itself.

Sentence A is incorrect because 'If I were an umbrella, I would lend it to you' has a pronoun error - 'I' and 'it' don't match. It should be 'I would lend you mine' or 'I would lend it to you' if the subject matched. Sentence B is correct because 'If I had an umbrella, I would lend it to you' properly uses second conditional with consistent pronouns and correct tense structure.

Sentence A is correct because it uses present simple 'If there is shortage... its price goes up' to state a general economic truth/fact. Sentence B is less appropriate because it uses future 'will go up' for what is clearly a general, recurring economic principle rather than a specific prediction about one instance.

Sentence A is correct because it uses proper first conditional structure with present simple 'If you are looking' and modal 'you may find'. Sentence B is incorrect because it uses 'will' in the if-clause 'If you will look' - 'will' should never appear in the if-clause of a conditional sentence.

Sentence A is incorrect because 'If you will stay' incorrectly uses 'will' in the if-clause. Sentence B is correct because 'If you are staying' properly uses present continuous to discuss arrangements or plans about staying another day. The present continuous is more natural than 'will stay' when discussing planned arrangements.

Option B uses the present perfect tense 'has written' which correctly indicates a completed action with relevance to the present. Option A is grammatically incorrect - 'is written' is passive voice and doesn't convey the intended meaning of someone completing the action of writing.

Option B is correct because 'have finished' is the present perfect tense form, which properly indicates a completed action. Option A incorrectly uses the present continuous 'are finished' which doesn't convey the meaning of completing an action.

Option B is correct because second conditional sentences use the simple past tense in the if-clause ('tried'), not 'would try'. The structure 'If + past tense, ... would + base verb' describes hypothetical present or future situations.

Option B is correct because this is a third conditional sentence describing a hypothetical past situation. The structure 'If + had + past participle, ... would have + past participle' is used for unreal past situations. Option A uses second conditional which doesn't convey the past meaning.

Option B is correct because 'have not seen' is the proper present perfect form to indicate experience or completed action. Option A uses 'are not seen' which is passive voice and grammatically incorrect in this context.

Option A is correct because second conditional sentences require simple past tense in the if-clause ('dyed'), not 'would dye'. The 'would' belongs only in the main clause, not the if-clause. Option B incorrectly places 'would' in the if-clause.

Option B is correct because second conditional uses simple past tense after 'if' ('tried'), not 'would try'. The modal verb 'would' appears only in the main clause, not in the if-clause.

Option B is correct because it uses the simple past 'came' in the if-clause, which is proper for second conditional sentences. Option A incorrectly uses 'would come' - the word 'would' should never appear in the if-clause.

Option A is correct because it uses the simple past tense 'abused' and 'became' to describe a habitual action or repeated pattern in the past. Option B incorrectly mixes future tense 'will abuse' with past tense 'became'.

Option B is correct because 'was' is the proper past tense form for the singular subject 'scarcity' in describing real or possible past situations. Option A uses 'were' which is typically reserved for hypothetical or counterfactual situations with singular subjects.

Option A is correct because it uses simple past tense 'interrupted' and 'got' to describe a habitual or repeated action pattern in the past. Option B uses conditional 'would interrupt' which changes the meaning from habitual past to hypothetical.

Third conditional for past unreal situations uses 'had + past participle' in the if-clause and 'would have + past participle' in the result clause. Option B correctly forms this structure, while A incorrectly uses 'would try' instead of 'had tried'.

Third conditional requires 'had + past participle' in the if-clause. Option A correctly uses 'had found', while B incorrectly uses 'would find' which is not grammatically valid in an if-clause for past situations.

The if-clause in third conditional must use 'had + past participle' exactly once. Option A correctly uses 'had come', while B incorrectly repeats 'had' with 'had had come' which is grammatically wrong.

In conditional sentences about real or likely future situations, the if-clause uses present tense. Option A correctly uses 'was', while B incorrectly uses 'will be' in the if-clause which is not grammatically standard.

Third conditional for past unreal situations requires 'would have + past participle' in the result clause to match 'had + past participle' in the if-clause. Option B correctly uses 'would have attended', while A incorrectly uses 'would attend' (present form) with a past if-clause.

The if-clause in third conditional uses 'had + past participle' without repetition. Option B correctly uses 'had come', while A incorrectly doubles 'had' with 'had had come' which is grammatically invalid.

The negative third conditional in the if-clause uses 'had not + past participle/wearing'. Option A correctly forms this as 'had not been wearing', while B incorrectly doubles 'had' with 'had had not' which is grammatically wrong.

Third conditional for past unreal situations uses 'had + past participle' in the if-clause. Option B correctly uses 'had got', while A incorrectly uses 'would get' which is not valid in an if-clause for past situations.

For real or likely future situations, the if-clause uses present simple tense. Option B correctly uses 'arrive', while A incorrectly uses 'would arrive' in the if-clause position which is not grammatically standard.

When expressing necessity or obligation about a requirement, 'must' is the correct modal verb. Option A correctly uses 'must reach' to indicate the necessity, while B uses 'would reach' which doesn't convey obligation appropriately.

Second conditional for hypothetical present situations uses 'if + subject + were + subject + would + bare infinitive'. Option A correctly uses 'would punish', while B incorrectly uses 'would have punished' (past form) for a present hypothetical situation.

In formal English, second conditional if-clauses use 'were' (subjunctive) rather than 'was'. Option A correctly uses 'If I were you', while B uses 'If I was you' which is considered informal or grammatically incorrect in standard English.

Sentence A uses the correct first conditional form 'If you have any difficulty' which refers to a possible future situation. Sentence B incorrectly uses 'would' after 'if' - in English, we never use 'would' in the if-clause of a conditional sentence. The correct structure is 'If + present tense' for first conditionals about real possibilities.

Sentence B correctly states 'You cannot pass unless you attend the college' - meaning attendance is necessary for passing. Sentence A contains a confusing double negative: 'cannot pass unless you do not attend' which actually means you must not attend to pass, which is illogical in an academic context.

Sentence A correctly uses 'in case' which means 'if it happens that.' Sentence B redundantly combines both 'if' and 'in case' together - this is incorrect because 'in case' already contains the conditional meaning. Using both creates unnecessary repetition and grammatical error.

Sentence A correctly uses 'otherwise I would have taken' showing past unreal conditional. Sentence B incorrectly says 'would have had taken' - this is grammatically wrong because after 'would have' we only use the past participle (taken), not 'had + past participle.' The perfect conditional 'would have taken' is correct.

Sentence A correctly uses 'otherwise he would not be' showing a past hypothetical result. Sentence B incorrectly uses 'had not to be' which is not a valid grammatical construction in this context. The correct form after 'otherwise' for hypothetical situations is 'would not be,' not 'had not to be.'

Sentence B correctly uses 'in case he comes here' which means 'if he happens to come here.' Sentence A incorrectly adds 'if' before 'in case,' creating redundancy. The word 'in case' already functions as a conditional connector, so adding 'if' before it is grammatically incorrect and repetitive.

Sentence A correctly states 'She cannot go to America unless she has a valid visa' - meaning a valid visa is necessary for travel. Sentence B illogically says 'unless she does not have a valid visa,' which with the double negative means she cannot go unless she lacks a visa - completely opposite of the logical requirement for international travel.

Sentence A correctly uses 'so long he is here' meaning 'as long as he is here' or 'during the time he is here.' Sentence B incorrectly adds 'in case' before 'so long,' creating confusion. 'So long' already functions as a time conjunction, and adding 'in case' makes the sentence grammatically incorrect and unclear.

Sentence A correctly uses 'so long the owner is out of station' meaning 'during the time the owner is away.' Sentence B incorrectly combines 'if' with 'so long,' which creates grammatical error. 'So long' already establishes the time condition, and adding 'if' before it is redundant and incorrect.

Sentence A correctly uses 'So long I am here I shall assist' meaning 'During the time I am here, I will help.' Sentence B incorrectly adds 'If' before 'so long,' creating grammatical error. 'So long' already functions as a time-based conjunction, and combining it with 'if' makes the sentence structure incorrect and redundant.

Sentence A correctly uses 'provided he also attends' - 'provided' functions as a conjunction meaning 'on the condition that.' Sentence B incorrectly adds 'if' before 'provided,' creating redundancy. Since 'provided' already establishes the condition, adding 'if' before it is grammatically incorrect and unnecessary.

The sentence has a structure of third conditional. The use of past perfect tense in the first clause necessitates the use of 'would have' in the second clause.