Answer:
support (a building or other structure) from below by laying a solid foundation below ground level or by substituting stronger for weaker materials.
Explanation:
This is the general definition of underpin
Answer:
Didn't is a contraction for did not, and means the same thing. Contractions generally carry a connotation of informality. Decide on the right level of formality for the audience, and use the appropriate form. (For instance, in most spoken language didn't is more common; did not is more common in formal writing.)
In this sentence, the word "throughout" is used as a preposition.
She wishes Romeo wasn't a Montague
