Final answer:
The correct pronoun usage for the given sentences is 'us' in sentence 5 and 'me' in sentence 6, as they are objects of the verb and preposition, respectively. Proper punctuation involves following rules to maintain clarity in writing, and subject-verb agreement is essential for choosing the right verb form.
Step-by-step explanation:
The sentences provided necessitate correct pronoun usage and punctuation. In sentence 5, 'They came and met us at the station,' the correct pronoun is 'us' because it is the object of the verb 'met.' In sentence 6, 'Here are some letters for you and me,' 'me' is again the correct choice because it is part of the object of the preposition 'for.'
Regarding the review questions which involve inserting or omitting commas, it is important to follow punctuation rules that ensure clarity and correct grammatical structure in writing. Furthermore, choosing the correct verb form such as 'is' versus 'are' or 'meets' versus 'meet' depends on the subject-verb agreement, which is a key aspect of English grammar.