He went to bed, for he was tired. (For = coordinating conjunction)

He went to bed, because he was tired. (Because = subordinating conjunction)

Is this correct? If so, I'm confused.

In all the examples and explanations I've found online it says 'for' is a preposition unless used in that particular way above, in which case it becomes a coordinating conjunction (FANBOYS). But to me it seems like 'for' has the exact same function and meaning as 'because' in the above example. Both could be replaced with 'due to the fact that...'

Why is 'because' subordinating but 'for' coordinating?

FANBOYS: for, and, nor, but, or, yet, so


  • 2
    Very good question, but I find the whole issue of coordinating and subordinating conjunctions arbitrary and confusing anyway. This is now taught to children at a far too elementary stage, when I was a child and teenager no one ever mentioned it.
    – BoldBen
    Commented Apr 4, 2021 at 5:36
  • 2
    "For" is either a preposition meaning "because", or a subordinator where it introduces infinitival clauses that have a subject. In your example, it's clearly a preposition.
    – BillJ
    Commented Apr 4, 2021 at 6:23
  • 2
    @BillJ Is your position that for does not belong in FANBOYS?
    – max norton
    Commented Apr 4, 2021 at 6:32
  • 3
    Grammarians don't use the acronym FANBOYS. Frankly, it's misleading. The coordinators consist of "and", "or", "but" and "nor". The "for" that introduces clauses is a subordinator, not a coordinator. As I said, it is a marker for infinitival clauses that contain a subject, as in "[For John to lose his temper like that] is highly unusual."
    – BillJ
    Commented Apr 4, 2021 at 6:46
  • 1
    @maxnorton Despite having certain similarities to coordinators, on balance "yet" (meaning "nevertheless") is best analysed as an adverb functioning as a concessive adjunct. Consider, for example, "You can look as fit as a fiddle and yet feel quite listless". Here it is "and" that marks the coordination relation, and since a clause can only contain one coordinator, it follows that "yet" can only be a modifier within the second coordinate.
    – BillJ
    Commented Apr 4, 2021 at 7:50

2 Answers 2


It's not surprising you're confused. There really isn't much difference in meaning between for and because here, but there's a difference in grammar, which is why for is traditionally classified as a coordinating conjunction and because as a subordinating conjunction.

The difference between subordinating conjunctions and coordinating conjunctions is the allowable word orders. Coordinating conjunctions have to come between the two phrases they are connecting, while there is no such requirement for subordinating conjunctions.

For example, you can say all of

He went to bed because he was tired,
He went to bed since he was tired,
He went to bed, for he was tired.

But if you try reversing the order of the clauses, only two of these conjunctions work. You can say:

Because he was tired, he went to bed,
Since he was tired, he went to bed,

but not

*For he was tired, he went to bed.

And that is why for is called a coordinating conjunction, while because and since are called subordinating conjunctions.


In response to Peter Shor's comment: "And that is why for is a coordinating conjunction, while because and since are subordinating conjunctions".

With items like "since" / "before" / "after", they uncontroversially occur as prepositions when they have an NP as complement, and there's no basis for assigning them to different categories according as they take an NP or a clause -- or no complement at all. Trad grammar has:

since the meeting:............. [preposition + noun]

since we arrived:............... [subordinating conjunction + sub clause]

(I hadn't seen her) since:.. [adverb, no complement]

This is just a matter of varying complementation, which is commonplace. Compare verbs:

I know her father ............. [verb + NP]

I know that he's ill............ [verb + clause]

I know.............................. [verb without complement]

Or noun:

a belief in God ..................... [noun + PP]

the belief that God exists......[noun + clause]

her beliefs.............................[noun without complement]

We need therefore to distinguish "since" from the genuine subordinators "that/whether", and then once we've done that "since" clearly belongs with other prepositions.

  • "Trad gram"? Sounds like a 70s glam rock band. What does PP stand for: Prepositional Phrase?
    – Mari-Lou A
    Commented Apr 5, 2021 at 7:08
  • This is not an answer. If this were an answer, you would say what part of speech for really was. This is in fact a long comment on my answer saying that it's wrong. Does Geoff Pullum classify for (meaning because) anywhere—is it an unusual conjunction or an unusual preposition? because it's certainly unusual either way. Commented Apr 6, 2021 at 11:52
  • 1
    I had already said what part of speech "for" belongs to in my first comment to the OP. This answer is indeed intended to be a detailed explanation of why your claim that "since" is a subordinating conjunction is wrong. The same applies to some other items such as "before".
    – BillJ
    Commented Apr 6, 2021 at 12:22
  • How does because "uncontroversially occur as a preposition"? The usual preposition is almost always because of. Because occurs in very narrow, often jocular, contexts ("because sicence", "because reasons") Commented Apr 21, 2023 at 14:23

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.