Hello Joe, not every "let" in english can be translated into "lasciare" in italiano. In your examples: -Let me do it (Lasciami (1)/lasciatemi farlo(2)" (1) I ask to one person to let me do something; (2) I ask to several persons to let me do something. -Let's go!: Andiamo! (我们走吧) -Let it be: Lascia stare! (don't try to change it) Other examples: Don't let me down: Non mi deludere. Whenever you use "lasciare", the use of lasciami, lasciarmi, lasciatemi depends on the subject, as verbes are conjugated in any tense in italian. Lasciami farlo!: "lascia" is the second person singular (you: tu) of the imperative mode: I ask YOU (one person) to let me do something. Non lasciarmi farlo!: "non lasciare" is the negative form of the imperative mode for the second person singular: I ask YOU (singular) not to let me do something. Lasciatemi farlo!: "lasciate" is the second person plural (you: voi) of the imperative mode: I ask YOU (several persons) to let me do something.