grammaticality - Plural words/singular modifiers

Something I've always been confused about even as a native English speaker...

Say, someone is discussing a concert and they say: "there was a huge amount of people there". Is this correct, or should it be "there were a huge amount of people there"? People is plural while huge amount is one singular thing. Can someone explain this to me?

Answer

A simple way of looking at it is: Words that come after a Preposition (e.g. "Of") are considered part of a Prepositional Phrase, and thus they're normally skipped as the "determining" Noun.

In your example, "amount" is the real Subject and not "people."

By the way, we normally say: "number" for people and other Countable Nouns. As in: "There was a huge number of people."

But, "There was a huge amount of water in the tank."