MODALS FOR NECESSITY (MUST)

Hello everyone. I hope you had a good weekend. 

This week we will be looking at modal verbs to express necessity. Today we look at Must, a modal verb that adds Obligation to the main verb.

Example 1 (statement with no obligation):
I go to work every morning.

Example 2 (obligation):
I must go to work every morning.

Some grammar books say that the modal verb must adds "internal obligation," that is...obligation from yourself. 

Example 3 (internal obligation):
I must call Anne. (Because it has been a long time since I've spoken to her and I would really like to know how she is.)

REMINDERS: 
a) Must should NEVER include the particle to. This is a very common error amongst students; I often hear students say sentences like **I must to go to work.** It sounds horrible.

b) The negative of must is must not or mustn't. 

Example 4:
I mustn't call Anne.

c) There is no equivalent past for must, so it's past is had to, or didn't have to in the negative. (We'll speak more about this tomorrow.) 

Example 5 (past):
I had to call Anne yesterday.

I hope you found this explanation clear. Have a great day and I'll see you tomorrow with a follow-up lesson!