What's your excuse?

I can't because I don't like it.

You have to buy a fish tank.

I can't my dog would break it. (And later attempt to eat it)

You have sign up for college.

I don't have a pen.

You have to brew some tea.

I can't because I have no tea leaves.

You have to make me a sandwich.

i cannot because i am allergic to all ingredients in a sandwich.
(no, i am not)

you have to hunt a deer

I can't because I love deer.

You have to do housework.

I can't because I don't own a house.

You have to get a new job.

I can't because I'm busy

You have to get me a hersheys chocolate

What's chocolate?

You have to buy me a puppy.

What's that?

You have to get me a new purse