Crossword puzzle clue "sit on a tack and then"

Sit on a tack and then ___

Hybrid car that runs a few seconds, then stops, then runs again, then stops again...?

Grammy nominated singer with the 2015 album "Sometimes I Sit and Think, and Sometimes I Just Sit"

Where a cat might sit when you sit down

Do this, then that, then this again

Place whose population was 1, then 2, then 0

Back then, back then

"First I'll read, then watch the movie, then..."