For your speech to sound more fluent and natural, it’s a good idea to avoid repeating words. Have a look at two ways of accomplishing this:
Missing words out
A simple way to avoid repeating words is to omit them.
Q: Is your name Sandra Smith?
A: It is.
(… It is Sandra Smith)
Q: Are you the manager here?
A: I am.
(… I am the manager here)
You don’t necessarily have to use this method when answering questions, you can use it in full sentences too:
She asked me to quit smoking, but I already had.
Man U won the games, but no-one thought they would.
Is this for me? Oh! You shouldn’t have.
Be careful to consider the context of your answer before answering. You don’t simply repeat the auxiliary:
Don’t forget to lock the car.
(present simple : auxiliary = do)
I already have.
(present perfect : auxiliary = have)
You can simply say the word to instead of the verb when the meaning is clear from the context.
A: Doesn’t your father drive?
B: No, he never learned to.
A: He should take his driving test.
B: Well, he doesn’t want to.