# The number of my opponents is or the number of my opponents are

I was reading the book "1100 Words", and for the section "Week 19, Day 1" I read the following: (eg https://lelb.net/1100-words-week-19-day-1/)

the number of the king’s opponents who were incarcerated* were legion

then I started to read exercises.

"the number of my followers is legion," said the flamboyant politician.

In the first example, we read "were" which is plural and the second example shows the same in the singular.

Which is correct and what's the difference if any?

• – Weather Vane Mar 3 '19 at 14:43
• Thanks for providing the link. But does this line "The number" is singular. "A number", however, is plural, and takes a plural verb properly fit the second example from the book? – Carlos Florian Mar 3 '19 at 14:50
• This question has been asked numerous times in various forms, and you can find some by searching for "number singular or plural stackexchange". – Weather Vane Mar 3 '19 at 14:53
• I asked a question about the examples from the book. It's easy to Google dictionary.com/browse/number but I had a question regarding this very example. For me it seems that both sentences are practically the same. But one of them uses plural and the second one uses singular, I'd love to know why? – Carlos Florian Mar 3 '19 at 14:58

The subject the number is singular:

The number is five.
The number is complex.

It doesn't matter what follows an of statement after number—the subject remains the singular number, regardless of what it might sound like.

The number of shoppers is large.
The number of mice is alarming.
The number of available vaccines is small.

And:

The number of the king's opponents who were incarcerated is legion.

However, you could also remove number of from the sentence, changing the subject of the sentence to one that is plural:

The king's opponents were legion.

the number of the king’s opponents who were incarcerated* were legion

I think it's because were legion refer to king’s opponents and not to "the number of".