Hi Felipe, 'Shall' is an auxiliary verb that behaves in a similar way to 'will'. Typically it is used to make suggestions or ask opinions on decisions. Because of the restricted use, it's usually found in the 1st person singular and plural forms (I / we). "Shall I cook chicken or fish?" - this is asking somebody's opinion about a future meal. "Shall we dance?" - this is a suggestion, a polite encouragement There are a few more rules, but these are the most common uses of it. Hope that helps a bit!

Just like will. I shall speak to you tomorrow. I shall go shopping later I shall see you soon.