1. because, as, since, for. Because is a conjunction that normally introduces a dependent clause and answers the question 'why?' (or, sometimes, 'how?'). It can relate directly to the statement made, as in
I came because I wanted to see you, which answers the (real or notional) question 'Why did you come?', or (like
for) it can relate to the status of the proposition, as in
I know he committed suicide, because his wife told me, which effectively answers the question 'How do you know he committed suicide?' and not the question 'Why did he commit suicide?'; in this sentence, the comma has an important structural function.
Because can also stand first in the sentence, as in
Because we missed the train, we had to wait a long time. It is also in order to use
because after an introductory
it is, it's, that's, this is, etc.:
It is because these Christian values are apparently being cast off by the present leadership of the Conservative Party...that many Christians are turning to the Alliance.—Church Times, 1985.
As and
since are often used at the beginning of a sentence, and (unlike
because) tend to emphasize the main statement rather than the reason.
For can only follow the main statement, and is a coordinating conjunction, whereas
because is a subordinating conjunction.
2. after negatives. Using
because after a negative statement (e.g.
I do not play cards because I enjoy good company, i.e. one containing a word such as
not or
never or including a word in
un- etc.) can technically cause ambiguity because it is not clear whether the reason given is an invalid one for a positive statement (i.e.
I do play cards, but not because...), or a valid one for a negative statement (i.e.
I do not play cards, and the reason is...). However, the context will often make the meaning clear:
Very many people...do not attend church because they are bored by ritualistic services—Lancashire Life, 1977
Her twin was told she was unlikely to have children because of her husband's low sperm count.—Daily Telegraph, 1979.
When necessary, a comma will usually remove any ambiguity:
The graphic equalizer is not for every hi-fi customer, because it does require some skill, time and patience in usage—Gramophone, 1976.
3. the reason is...because.... The reason for this was because I was the only one who could sign it, because the account was in my name—Ben Elton, 1991.
This construction is often rejected on grounds of style in favour of
the reason is...that..., since
because is logically redundant after
reason. But redundancy is a regular component of idiom, and given that both constructions are common it is becoming harder to insist on the point. In the following example, it would weaken the statement considerably to replace
because with
that:
The minipill was developed for one reason alone: because it was believed to provide safe contraception—New Scientist, 1970.
However,
because of should be avoided in this kind of construction:
☒The reason we have no light is because of a broken fuse should read
The reason we have no light is that the fuse is broken. 4. because of. With the reservation given in the last paragraph,
because of is a legitimate use in many positions in a sentence:
Because of the deterioration of the sugar in the blood it was decided, after consultation, to carry out an exchange blood transfusion—Glasgow Herald, 1970
He'd have to watch his step...not to make a hash of things, because of over-anxiety—J. Wainwright, 1976.
5. at the head of a dependent clause governing a main clause, as in
Because we don't explicitly ask these questions doesn't mean they aren't answered—New Yorker, 1986.
This kind of construction, though common in speech, is awkward in written English because the main clause is uncomfortably delayed, and the sentence should be recast, e.g.
These questions are still answered even though we don't explicitly ask them.
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