Choisir entre for et since dans des phrases affirmatives Exercice fondamental

I have been waiting for you sincefor two hours.

He has stared at us sincefor we arrived.

We haven't eaten such a delicious cake forsince last time we visited you.

They have been working on this project sincefor five weeks.

She has been looking for a solution forsince twenty minutes.

He has been trying to finish this exercise sincefor half an hour.

She hasn't talked to John forsince Christmas.

I have written to you every day sincefor you left.

They have been studying in the library sincefor three hours.

You haven't looked so tired sincefor last end-of-term examination.