Primary helping verbs:
1. be (am, is, are, was, were, being, been)
2. have (has, have, had, having)
3. do (does, did, doing)
Modal helping verbs:
1. can
2. could
3. may
4. might
5. must
6. shall
7. should
8. will
9. would
These verbs help other verbs form different tenses, moods, and voices. They are always used with a main verb to create a verb phrase.
For example:
* I am going to the store. (am is the helping verb, going is the main verb)
* She has been working all day. (has and been are helping verbs, working is the main verb)
* We could have finished the project. (could and have are helping verbs, finished is the main verb)