English Grammar and Usage

Option D is correct because it uses proper capitalization. 'Mary' is a proper noun and must be capitalized, and 'I' is always capitalized as the first-person pronoun. Options A, B, and C are incorrect because they fail to capitalize either 'Mary' or 'I'. Capitalization rules for proper nouns and the pronoun 'I' are fundamental in English grammar.

Option B incorrectly mixes present tense 'leaves' with past tense 'did not arrive' in the same sentence, creating a timeline contradiction. Option D wrongly uses present continuous 'are walking' alongside past tense 'happened', breaking the narrative flow. Options A and C maintain consistent tense usage within their clauses.

Option B is correct because it maintains pronoun consistency. The subject I should be followed by I, not you, when referring back to the same person. Option A incorrectly shifts to second-person you.

Option D is the most polite and professionally appropriate refusal, offering a valid personal reason. Options A and C are informal or grammatically poor, while B is rude and unprofessional for workplace communication.

The correct preposition is 'for' - we feel admiration 'for' someone. The phrase 'admiration for' is standard English. 'To', 'with', and 'from' don't collocate with admiration in this context.

Option A uses the correct future perfect tense structure in German: 'werden...haben' with the past participle 'beendet' and the subject 'wir'. Option B lacks the subject, C uses the wrong participle 'geendet' (beendet is correct), and D incorrectly uses 'sein' instead of 'haben'.

This tests Spanish indefinite pronouns. 'La policía preguntó a alguna gente' - 'alguna gente' (some people) is correct after 'a' (personal a). 'Nadie supo contestarle' - 'nadie' (nobody) is the subject. The phrase means 'The police asked some people who were there, but nobody knew how to answer.'

This describes an action that was completed before another past action (pluperfect). The past perfect (pluscuamperfecto) 'había apagado' indicates that when the speaker returned (past), the wife had already turned off the lights (action completed before that past moment).

With time words like 'today', 'yesterday', 'tomorrow' used as nouns, we use possessive 's' but without 'the'. 'Today's' (A) is correct. 'The today's' (B) is wrong - we don't use 'the' with these possessives. 'A today's' (C) is wrong - never use 'a'. 'This day's' (D) is incorrect form.

After the verb 'hear' in past tense ('I heard'), we use the bare infinitive (base form) without 'to' when the action is being performed. 'I heard you sing' (B) is grammatically correct. 'To sing' would use the infinitive marker incorrectly after 'heard'.

'It has been [time period] since' is the standard construction for describing elapsed time from a past event to the present. 'Since' functions as a conjunction connecting the two time references. 'When' would create a relative clause (when I last saw you), 'that' doesn't fit grammatically, and 'if' changes the meaning to a conditional.

The phrase "last month" indicates a completed action in the past, so we use the simple past tense "bought". Present perfect "have bought" connects past to present and needs a time reference like "since" or "already". "Buyed" is misspelled - the past form of buy is "bought" (irregular verb). "Did bought" is grammatically incorrect because after "did" we use the base form "buy".

In questions about the past, we use the auxiliary 'did' + subject + base verb (did you talk). The base form of 'talk' is required, not 'talked.' 'You talked' is a statement, not a question.