Please, explain the difference!

I'm a little bit confused with how to use such French words as "un désir, un envie, un souhait et une volonté". Could you please explain the difference as clear as possible and give examples! Merci beaucoup d'avance!

The other word chain is "souci" vs "soin".

Привет, Анна! This is a tough question because thesе nouns are very similar in meaning. Désir, envie, and souhait are almost synonymous and can be often used interchangeably. However, there are of course slight nuances, and some fixed expressions require the use of one or the other. The best way to learn them is by memorizing common expressions and reading as much as possible. Below, I've written a few usage examples to help you.

désir (m) = desire, wish

Examples:
le désir to faire quelque chose = the desire to do something
Anna a exprimé son désir d'apprendre une nouvelle langue. = Anna expressed her desire (wish) to learn a new language.
Nous sommes prêts à satisfaire tous vos désirs  = We are ready to satisfy all your wishes (requests). [common in hotel ads]
le désir de réussir = the will (desire, wish) to succeed


envie (f) = desire, longing, craving

Examples:
J'ai une envie de sandwich au pâté. = I have a craving for a paté (паштет). sandwich.
avoir envie de faire quelque chose = to want to do something / to feel like doing something
J'ai envie de voyager. = I feel like traveling.
J'ai envie de jouer au tennis. = I want to play tennis. / I feel like playing tennis.
J'ai envie de cette voiture ! = I want this car!


souhait (m) = wish, desire

Examples:
faire des souhaits = to make wishes
tous nos souhaits de bonne année = our best wishes for the new year
À vos souhaits (à tes souhaits) ! = Bless you! Будьте здоровы (будь здоров)!


volonté (f) = will, wish, intention

Examples:
respecter la volonté de quelqu'un = to respect someone's wishes
ses dernières volontés = his/her last wishes
imposer sa volonté à quelqu'un = to impose one's will on someone
Elle lui a dit sa volonté de se marier. = She told him of her intention to get married.


Quant à ("As for...," "Что касается...") les mots 'souci' et 'soin', they have very different meanings.

souci (m) = worry, preoccupation

Je suis en souci de sa santé. = I'm worried (concerned) with his/her health.
Elle est sans souci. = She is without worries.


soin = care

On lui a confié le soin de la maison. = He was entrusted to take care of the house.
Prends soin de toi = Take care of yourself.
faire quelque chose sans soin = to do something carelessly

Надеюсь, что помогает! Удачного дня!!  -Роберт