Base Ta - ooph la la

Have you ever verbed – verb (base TA) + koto ga aru

Iku – itte, itta

Tokyo ni itta koto ga aru? Have you ever been to Tokyo?

Hai, Tokyo ni itta koto ga arimasu. Yes I have been to Tokyo before.

Sushi o tabeta koto ga aru? Iie, sushi wa tabeta koto wa arimasen.