The difference between there is and there are relates to numbers: we use there is to talk about one subject (singular), and there are to talk about more than one subject (plural).
The basic rules are:
- A singular subject takes a singular verb
- A plural subject takes a plural verb.
- Subject and verb must always agree. (You can read more about this in subject/verb agreement.)
- There is the Droid you are looking for.
- There are the Droids you are looking for.
We use there is if the subject of the sentence is a singular noun or pronoun (‘man’, ‘woman’, ‘child’, etc.):
- There is the cat.
- There is my son.
- There is the park.
We use there are if the subject of a sentence is a plural noun or pronoun (‘people’, ‘cats’, ‘dogs’, ‘robots’):
- There are my friends.
- There are two pairs of socks in the drawer.
- There are more than 20 people at this party.