LassLass is the rootformroot form of the Verb lassen (Infinitivinfinitive) and it's useused as Imperativformthe imperative here. That's why you just drop out the ending en . And because it is Imperativimperative, the Verbverb is at the beginning. The Verb machenverb machen is at the end and in it's Infinitivits infinitive form, because it is the 2nd verb in the sentence.