Which is correct?
The cost of the campaign is too high.
The costs of the campaign are too high.
It depends on what is meant. If the speaker essentially means ‘We can’t afford it: it’s too expensive’, then cost is correct: the emphasis is on the total amount needed.
If the speaker means ‘We must be careful how we spend our campaign money’, then costs is correct: the emphasis is on the individual items of expenditure, and the implication is that they need to be looked at and reduced.
Dutch speakers should bear in mind that Dutch often uses kosten where English uses cost. So whenever you find yourself using costs, ask yourself whether the focus of the meaning is on a single sum covering everything or on the various individual items. Then you’ll know whether costs is correct, or whether you should be using cost instead.
When you use cost, use the structure the cost of ____. When you use costs, use the structure ____ costs. For example,
the cost of living living costs
the cost of the campaign campaign costs
the cost of travel travel costs
Although doing things the other way round won’t result in ungrammatical sentences, the above structures are the ones most often found in English.
©2014 Baxter Publishing, Hilversum, The Netherlands