Student or Learner
4th shipment must have/has happened before last friday
i am sure the correct sentence should be 4th shipment must have happened..
but i would like to know, what kind of verb 'must' is here?
must is superlative form, aight? please enlighten me on the usage of must.
"Must" is also a "modal verb." Such verbs give a "mood" to the main verb in a sentence.
I eat cake. ("like" is the main verb)
I can eat cake. ("can" gives you more information about the verb "like;" it tells you that I have the ability to eat cake; or it "sets the mood" of the verb)
I should eat cake. ("should" also sets the mood here; it tells you that it would be a good idea for me to eat cake)
I may eat cake. ("may" tells you that it is a possibility that I will eat cake)
I must eat cake. ("must" in this case tells you something that I have to do)
I must have eaten cake. ("must" plus the Present Perfect--"have eaten"--tells you that I am approximately 95% certain that I ate cake)
I hope this helps,