Which verb should I use?

The Wall Street Journal's stylebook entry on collective nouns advises that with words such as variety, number and total, [and group] a rule of thumb is to use a singular verb when the article "the" precedes the noun and a plural verb when the article "a" is used.

So "The number," "the total," and "the variety" have a singular meaning. But "a number," "a total," and "a variety" take a plural verb.

Well that's interesting, and useful.

"The army" is usually singular. But what about "The police"?

Or even "The Beatles"?

Don't tell Elvis Costello. (Oliver's Army are on their way...)

That extract I quoted only applies to words such as variety, number, total and group, e.g. a variety of drinks are available, the variety of drinks is amazing!

As for collective or group nouns, in British English they can take either singular or plural verb forms depending on the context. For example, "the team is in the dressing room" refers to the team as a group, whilst "the team are fighting among themselves" refers to the team as individuals. Also in sports contexts e.g. "Germany have won the competition.", "Madrid have lost three consecutive matches.", etc.

In American English, collective nouns almost invariably take singular verb forms.

Makes ya fink, dunnit?