Question

Thank you. Do you say "he will become Thane of Cowdor OR the Thane of Cowdor?

I looked up prophesy in the dictionary and found out that it can be both a noun or a verb.
(to Prophesy: to say what will happen in the future, especially using religious or magical knowledge [= foretell]
He prophesied that a flood would cover the earth.)
2)I need to check this sentence which is grammatically wrong:
Spanish had big and slow ships, so the English naval army defeated the former, because their ships were lower, faster and armed with long-range guns.
Corrections:Spanish ships were heavy and slow whereas the English ones were ....

Answer 1

With or without "the" is fine.

Did you see the link I gave you re prophesy/prophecy?

Your correction for #2 is good. <b>Put a comma between the two independent clauses!!</b>