Excuse me, (am/is/are/do/don't/does/doesn't) you speak English?

"Where's David?" "I (...) know."

What's funny? Why (...) you laughing?

"What (...) your sister do?" "She's a doctor."

It (...) raining.

I (...) want to go out in the rain.

"Where (...) you come from?" "Finland."

How much (...) it cost to send a letter to Germany?

Stephan is a good tennis player, but he (...) play very often.