Choose the Correct Word (Grammar)

The sentence describes a situation starting in the past and continuing to the present. Present Perfect tense is used for actions that began in the past and continue to or have relevance in the present. "I have not seen him since his mother left the town" is correct because the action of not seeing him started when the mother left and continues to the present. "Had not seen" would be used only if followed by another past event.

 'Go' is the correct option.

"Would not" is the correct answer.

Simple past is being used, so blank will be filled with the same tense.

The phrase as though is used to describe a hypothetical situation or appearance. It functions as a conjunction here to link the action to the comparison.

The sentence describes a completed action in the past while another action was in progress. Fell is the simple past tense of fall, which fits the narrative sequence.

 "Might not" is the correct answer. The best expression would have been simple present 'don't'. 'Going To' is indicative of future tense. So, the subsequent cannot use future tense again. Among the available options, 'might not' fits better than other options.

In conditional clauses starting with unless, the present simple tense is used to refer to a future condition. Works is the correct third-person singular form.

 "Because of" is the correct answre.

 "had told it to" is the correct answer. When the main clause uses could have + past participle, conditional clause is in past perfect.

The structure so + adjective + that is used to express cause and effect. It indicates that the speed of the tonga caused the passenger to hold on tightly.

In a first conditional sentence, the if-clause uses the present simple tense, while the main clause uses the future tense. Go is the correct present simple form.

This is a third conditional sentence, which uses the past perfect tense in the if-clause. Waited is the correct past participle form to complete the structure.

The Past Perfect expresses the idea that something occurred before another action in the past.

 "They decided" is the correct answer. We do not use however/but/ yet together with although.

The phrase who ever is used to refer to the persons mentioned. It acts as the subject of the relative clause.

"Had had" is the correct answer. Past perfect forms are a feature of if-clauses in the third type of conditional sentence when we are explaining past actions or regretting past inaction. 

The sentence is in the past tense, as indicated by the main clause was. Therefore, the relative clause must also be in the past tense, making wanted the correct choice.

This is a reported speech sentence where the original condition was in the past. Would have lent is the correct form to reflect the past conditional.

The past perfect continuous tense is required here to show an action that was ongoing up to a point in the past. That I had been writing in correctly completes the relative clause.

Superlative adjectives, such as biggest, are always preceded by the definite article the.

However is the correct conjunctive adverb to show a contrast between the two clauses. It signals that despite not feeling well, the situation has improved.

Give rise to is a standard idiom meaning to cause something to happen. It is the correct collocation for describing the effect of unhygienic circumstances.

<span style="font-size:" 11.9999990463257px;="">To talk about future in a conditional sentence, we use simple present after until.