I would rather take a taxi than walk.
Your brother's daughter is your niece.
Are you mad ?
Are you out of mind ?
Why are you in a bad mood ?
Why are you cranky ?
I'm like you a lot.
I'm so into you.
I'm fit and healthy.
I'm fit as a fiddle.
I'm a bit busy.
I'm a bit tied up.
I'm very busy.
I'm swamped.