This document provides instruction on several English grammar forms:
1) Forms of "to be" + "going to" + verb (infinitive) to talk about intentions and make predictions.
2) "Must"/"mustn't" + verb to say something is important/unimportant to do.
3) "Will" + verb to make offers to help.
4) "Should"/"shouldn't" to say something is a good/bad idea.
5) "If" vs. "when" - "if" is unsure, "when" is sure but not specific time.
6) Present perfect to talk about actions that happened some time up to now