What the exam asks
The stem is always Which choice completes the text so that it conforms to the conventions of Standard English? The choices tell you what’s being tested:
| If the choices look like… | The item tests… |
|---|---|
| is / being / to be / having been | Finiteness: does the subject still need a main verb? |
| damaged / was damaged / is damaged / has been damaged | Finiteness in reverse: is there already a main verb, so the blank needs a participle? |
| discharges / discharged / had discharged / will have discharged | Tense and aspect: which time frame fits? |
| detect / detected / detecting / to detect | Form after a helping verb or in a parallel pair |
| falls / will fall / would fall / had fallen | Conditionals |
Core ideas
Finite vs. nonfinite verbs
A finite verb has tense and can be the main verb of a clause: is, was, provides, provided, has provided, had crashed, will have traveled. A nonfinite form can’t be a main verb on its own:
| Nonfinite form | Examples | Typical job |
|---|---|---|
| infinitive | to provide, to be | purpose, or after certain verbs and nouns (decision to restore) |
| present participle / gerund | providing, being | modifier phrase, or a noun (Tagging birds is hard) |
| past participle used alone | , |