Need help from native speakers

[HUFS1999]

"Moving toward the stadium was a great number of hooligans."

Can you find anything wrong with the above sentence?
The answer says that as the subject has been inverted, the verb "was" should be corrected into "were". But I was just wondering if "moving toward the stadium" can be accepted as a Gerund. Of course, I know that would make a slight difference to the sentence. But I`m not sure of WHAT THE DIFFERENCE IS!! I am desperate for it. What`s your opinion?

Thanx in advance.

[Clark]

"Moving toward the stadium was a great number of hooligans."

Can you find anything wrong with the above sentence?
The answer says that as the subject has been inverted, the verb "was" should be corrected into "were". But I was just wondering if "moving toward the stadium" can be accepted as a Gerund. Of course, I know that would make a slight difference to the sentence. But I`m not sure of WHAT THE DIFFERENCE IS!! I am desperate for it. What`s your opinion?

Thanx in advance.

In your sentence the subject is 'a great number of hooligans'. It's a case of emphatic inversion (the predicate precedes the subject). We can rephrase the sentence:

A great number of hooligans were moving toward the stadium.

So the auxiliary 'to be' has to be adjusted to the subject. 'A number of smth' normally agrees with a plural verb (unlike 'the number of sth' which agrees with a singular verb).

Suggesting that 'moving toward the stadium' is a subject doesn't make any sense, though from the point of view of the formal sentence structure it may look like a subject.