subject-verb agreement

Question

Is this sentence correct?

There is at least two ways to find this answer.

Grammar checkers want to change it to "are". But isn't the subject "answer"? Because "ways" seems to be part of a prepositional phrase.

Answer 1

Ask yourself, "What is THERE?" Then answer yourself, "TWO WAYS are". We could get more complicated, but why?

Answer 2

This is actually an example of a "null subject" sentence!

"Answer" is the direct object - it is the thing being found.

"two ways" is the subject complement - it is equal to the subject, appearing at the other side of a linking verb tied to the null subject "there". Note that the phrase "two ways" is definitely plural.

"at least" is an adverbial phrase quantifying the subject complement "two ways".

"There" is the null subject.

"There are" is known as the existential clause and in this sentence it is used to express that two ways exist.

To simplify my answer, "there" links the verb to the subject complement. If the subject complement is singular (one way), you get a singular verb: There is one way to find this answer. If the subject complement is plural (two ways), you get a plural verb: There are two ways to find this answer.

This is confusing because normally the verb agrees with the subject, not the subject complement, but there is no real subject here, and the verb has to have some context to form its number (singular or plural).

That's pretty much what's going on!