is the base form of the verb. It can take the forms of am/is/are (in the present) and was/were (in the past).
It may be used as infinitive:
- I want to be famous.
- She’s decided to be more patient.
is the past participle, used in Present Perfect Simple and Continuous:
- I have been married for ten years.
- I have been working here for a year.
is gerund or present participle, used after verbs that are followed by ING-ending, for example:
- I love being with my family.
- I hate being alone.
or in the Continuous Passive Voice:
- My car is being repaired. (=Someone is repairing it now)
- The kids were being looked after by my parents while I was on holiday. (My parents were looking after them)