Quel que/qui que/quoi que/quelque...que

Question

Hello Kwiziq members, I know we haven't talked about the topic of expressing "no matter what/who/when/how/where" here? But can we create an article and talk about this in depth?

1. How to use quel que/qui que/quoi que/quelque que in a sentence?

2. How to use peu importe in a sentence?

3. What is the difference between these two?

Merci beaucoup!

Céline Pickard · Accepted Answer

Bonjour Winston,
Here is my "little" contribution, which I hope, you do find it useful. 
- ‘quel que’ (quelle que, quels que, quelles que) is a relative pronoun immediately followed by a personal pronoun, and it can be followed by ‘être’, a ‘verbe d’état’ (link here) or with ‘devoir’ and ‘pouvoir’ in Le Subjunctive.

Quel que soit ton choix… = whichever choice you make ...
Toute personne, quelle qu’elle soit… = anyone, whoever it may be...

- ‘quelque … que’: ‘quelque’ can be used as an indefinite adjective or an adverb. It is very rare to use ‘quelque… que’ as it is extremely formal.
adjective:
Quelques ingénieurs que vous soyez, vous devrez faire bien mieux = whatever engineer you are, you’ll have to do much better
Adverb:
Quelque habilement que vous pensiez, vous ne convaincrez personne = however skillfully you think, you will not convince anyone
 
This expression is more used this way:

Il faut que tu t’adaptes de quelque façon que ce soit = you will have to adapt in any way
Pour quelque raison que ce soit, tu ne m’en as pas parlé = for whatever reason, you didn’t talk to me about it

- ‘qui que ...’ is the equivalent to ‘quiconque, quelque personne que ce soit’ (whoever, whichever person it is).
Qui que ce soit qui vous l'ait dit, il s'est trompé = whoever told you, he was mistaken
- ‘quoi que’ : follow the link here to a previous answer
- ‘peu importe’:

Peu importe qui que ce soit … = no matter who it is
Peu importe que ce soit Noël... = it doesn't matter that it is Christmas...
Si tu en parles à qui que ce soit… = if you speak to anybody...
Peu importe ce que tu souhaites faire, c’est comme ça = no matter what you might want to do, that’s how it is
Peu importe que tu l’aimes, ce sera toujours un goujat = No matter how much you love him, he’ll always be a cad.

I hope this is helpful.
Bonne journée !