[Grammar] Plural or singular verb

[Julie17]

Which sentence is correct:

1) This year's theme is the future requirements of European business.
2) This year's theme are the future requirements of European business.

 

[Rover_KE]

As an English teacher yourself, Julie, you should be able to give us your own considered opinion.

 

[Julie17]

At first I wanted to mark sentence 1 wrong, but after turning a few pages I've found similar examples in Swan's 'Practical English' (p. 522): 'A serious problem is wasps.' And of course I know that in general the verb agrees with the subject of the sentence. Still I was not sure about this sentence - probably because of interference of my mother tongue.

Are there any examples in the English language where this rule does not apply?

 

[Rover_KE]

'This year's theme is...' is correct.

I cannot think of any exceptions to the rule, except perhaps 'The wages of sin is death', but there is an explanation of that apparent anomaly here.

Rover