"Sans doute qu'il y aura de la pluie alors !" Sans doute qu'il y aura de la pluie alors ! No doubt there will be rain then! Why is it "qu'il y aura" instead of just "il y aura"?

"Pendant que j'étais au restaurant, Marie est venue me voir." Pendant que j'étais au restaurant, Marie est venue me voir. While I was at the restaurant, Mary came to see me. Why is it "pendant que" instead of just "pendant"?

"I had to..." 'J'ai du' versus 'Je devais' i wanted to a tell a friend "I had to look it up" and i wasn't sure which form was correct.

"I had to..." 'J'ai du' versus 'Je devais' I wanted to tell a friend that "I had to look it up" and I wasn't sure which form was appropriate.

I lost myself in your arms Je me suis perdue dans tes bras

what happened what happened to you? Ce qui vous est arrivé what happened? Qu'est-il arrivé Tu choisis ce qui est bon pour toi. you choose that which is good for you (qui goes before a verb, que before a noun/prounoun) je sais ce que je sais

one question Avez-vous un numéro de téléphone où l'on peut vous joindre ? Do you have a telephone number where we can contact you?

"l'on peut vous joindre" Avez-vous un numéro de téléphone où l'on peut vous joindre ? Do you have a telephone number where we can contact you? why is it "l'on" instead of just "on"?

"with whom" I'm trying to say the phrase: "i'm looking for a friend with whom to study french." Would I say: "je cherche un ami avec qui de parler francais"?