Grammatical number of "a specified number of people" [duplicate]

Question

In this sentence, which is correct, is or are?

We will not stop operating until a specified number of weak events [is/are] detected.

My feeling is that the verb should agree with number, not events, thus I'd use is. But there is disagreement here at work.

Also, what is the name of the phrase "of weak events" in this sentence? If I knew that to begin with I'd probably have been able to look up the answer.

Answer 1

Firstly, it is counter-productive to analyse 'of weak events' here in the same way as one would analyse say 'of weak events' in 'Properties of weak events'. The of belongs rather with a [specified] number of, and a number of is a compound (multi-word) quantifier. Contrast The numbers of locomotives over 50 years old are getting hard to read and need cleaning (eg locomotives number 11031, 11032, 11033...) (prepositional phrase) with The number of locomotives over 50 years old is very low (we've only six left now) (compound quantifier usage). See http://www.myenglishpages.com/site_php_files/grammar-lesson-quantifiers.php .

Secondly, as Reg suggests, the situation is complicated by what the meaning of the statement is (though 'a number' is singular, it is almost certainly referring to more than one event, and this is taken into consideration in 'logical concord' - see http://grammartips.homestead.com/number.html for a discussion of this particular quantifier. Different quantifiers are handled differently, and not always predictably.)

And thirdly,

We will not stop operating until a specified number of weak events have been detected.

is probably intended.

Answer 2

"Of weak events" is a prepositional phrase. Of is the preposition and weak events is the object. As for your initial question, concord always applies to the relationship between the verb and the object in question. In this instance, number is, indeed, the object, so you should use is. The prepositional phrase merely modifies the object and should not be taken into consideration for this.

When in doubt, always ask which object is referenced by the verb. You will then have your answer.

Answer 3

This issue demonstrates an inconsistency of the regular practice of English language.

• There is a truck load waiting outside.
• There is a truck load of stuffs waiting outside.
• There are a truck load of people waiting outside.

IMO, is/are depends on the object of focus.

The focus is on people with the {truck load} used as adjective.

• There are {many} people waiting outside
• There are {a lot of} people waiting outside.
• There are {a truck load of} people waiting outside.
• There are {a ton of} people waiting outside.

The focus is on {truck load}:

• There is a truck load outside.
• There is a truck of load vegetables outside.
• There is a truck of load cabbages outside.
• There is a ton of people waiting outside.

IMO, both forms are valid. Simply a flexibility afforded by the ambiguity-prone English language to allow you to denominate the focus of your speech thro simple means rather than thro extreme and complex paradigms of other languages.