C'est moi qui est tout seul...or?

Question

do you use 3rd or 1st person

if you do use 3rd person than do you say

c'est moi qui l'a fait or l'ai fait

and do you use 3rd or 1st person on any sentence starting with c'est moi qui

and c'est aujourdh'ui que j'aurais du y aller

i should've gone today-do french people say it like that

what does je me tiens a dormir mean

and go to my questions and answer some of my other fench help ones please

Thaks for yalls help

Answer 1

C'est moi qui l'a fait.

Yes, I remember that from my French lessons. You have to use the third person.

Answer 2

C'est moi qui l'ai fait. C'est moi qui suis tout seul. You use the 1st person. Using the third person is a very common mystake that kids make.

C'est aujourd'h*i que j'aurais du y aller is totally correct, but it insists on today. More simply, you can say j'aurais du y aller aujourd'h*i. But your proposition is completely correct.

Je me tiens à dormir doesn't mean anything. Either it's je tiens à dormir which means It's really important for me to sleep, or je me prépare à dormir which means I'm about to go to sleep.