Oui, si, non, moi, aussi

 These are commonly used words in French:

Oui: Yes

Si: Yes (used to contradict a negative question or statement, like "yes, but...," or to emphasize a contrasting affirmation)

Non: No

Moi: Me/I (pronoun, used for emphasis or contrast)

Aussi: Also/Too

Here's an example of how they might be used in a sentence:

"Est-ce que tu veux du café ?" (Do you want some coffee?)

"Oui, j'en veux." (Yes, I want some.)

"Non, je n'en veux pas." (No, I don't want any.)

"Si, j'en veux." (Yes, I do want some.) [Contradicting a negative question]

"Moi aussi, j'en veux." (I want some too.) [Emphasizing agreement]