during

during — предлог, после него идёт существительное (не предложение):

• during + noun: during the film, during the meeting, during the summer

I fell asleep during the film. Nobody spoke during the meeting. It rained during our trip.

Если нужно сказать «пока происходило что-то» с подлежащим и глаголом (пока я смотрел, пока она готовила) — нужен while, не during.