about 'half of...'

[3doubler]

Dear instructors,

Whenever I try to recognize the subject of sentences including 'half of / all of / much of / ,...', I'm having difficulties to identify the subject of the sentence. For example,

More than half of the students ( is / are ) of 13 years old.

I can not exactly find out what a word plays the role of the subject in this sentence. 'half of' or 'the students'? Does 'Half of' modify 'the students' or 'of the students' modify 'Half of'?
I sincerely hope to know the rule to clarify this.

Thank you!

[RonPurewal]

In general, "half of ____" (or "N% of ____", or any similar construction) will be ...
... singular if "____" is singular;
... plural if "____" is plural.

So, since "students" is plural, "half of the students" is also plural. ("Half of a chocolate bar" would be singular.)

If this sort of thing is ever tested on the exam, it will certainly be tested this way.

[3doubler]

In general, "half of ____" (or "N% of ____", or any similar construction) will be ...
... singular if "____" is singular;
... plural if "____" is plural.

So, since "students" is plural, "half of the students" is also plural. ("Half of a chocolate bar" would be singular.)

If this sort of thing is ever tested on the exam, it will certainly be tested this way.

Thank you for your help sir

[RonPurewal]

You're welcome.