Hi, all! I need your nativespeakers’s help) I want to clarify the the difference between “is to come” and “is coming”. When we should use the first one and when the second one? Could you give me some examples?

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Answer

Although both talk about the future, they are very different. “Is to come” is more of a hope or expectation. An example is “the best is yet to come”. 
“Is coming” is more like a prediction, or informing you of what will happen soon. 
“Where is his Lordship?”
“ He is (just) coming.”

Answer

Come : To move or travel towards or into a place. (VERB)

Coming: The act of arriving; an arrival. (ADJECTIVE)
I hope I've helped ❤️

Answer

Context is always important, but here are the basic uses.

Students are to arrive by 9 a.m. Monday. [obligation]

Students are arriving by 9 a.m. Monday. [arrangement]

Stusents are arriving (now). [action in progress]

More information:
www.ef.com/ca/english-resources/english-grammar/future