Adverbs

Verbs

Agreement:

- Single or plural. Consistent with the subject.

Tense:

- Past, present, future.

Voice:

- Active/passive.

Key Points:

1. Subject & Verb Agreement:

- If there are options with both singular and plural forms, consider the subject's number first.

- The main sentence subject and verb should agree.

- The clause subject and verb should agree.

- The Prepositional Phrase is never the Subject.

- The noun after a preposition is never the subject.

- The noun before a preposition is possibly the subject.

- Inversion (inverted sentence): verb comes before subject.

2. Tense:

- Consider singular or plural first, then tense.

- Present Perfect:

- Should appear together with signal words such as: for, since, over, during, by, by the time.

- If there are no signal words or obvious logic, do not use the present perfect.

- Past Perfect:

- Refers to the action that came first when there are two past actions.

- Signal words: by, by the time, before + past time.

- Verb Tenses:

- Consistency in the same paragraph is important for the timeline; consider the time markers.

- have/has done indicates the present past.

- had done indicates the past past and requires a past time marker, such as before...

- Signal words for the present perfect: for, since, over, during, by, by the time.

- Over/during + a period of time.

- If there is no logical connection requiring the use of the present perfect tense in the context, the present perfect tense and these signal words should either appear together or not at all.

3. Past Participle:

- Past participle cannot function as a predicate alone (grown, begun).

- have/be can be followed by a past participle; have/be + past participle can be used as a predicate.

- have/be + simple past is always incorrect (when the past tense and past participle have different spellings, grew-grown).

- The past tense indicates an active voice; be + past participle indicates a passive voice.

4. Would/Could:

- would/could + of is always incorrect; it should be would/could have.

- Would + verb:

- Past Future: When he was a child, people knew that he would become a great thinker.

- Hypothetical: If I knew ACT is so hard, I would start studying ACT much earlier.