As conjunctions joining two clauses, they mean exactly the same thing and are interchangeable: "Although the flat was small, it suited us" and "Though the flat was small, it suited us" are both correct. Though is the more informal of the two, and it has one job although cannot do — trailing at the end of a sentence to mean "however": "The rent was high. We took it, though."
Where they overlap
Introducing a contrast at the start or middle of a sentence, the two words are genuinely interchangeable. There is no difference of meaning to worry about:
- Although he'd been warned, he went anyway.
- Though he'd been warned, he went anyway.
- She agreed to help, although she was exhausted.
The only thing separating them here is register. Although is a shade more formal and reads better at the opening of a sentence in careful prose; though is lighter, more conversational, and much commoner in speech.
Where only though works
Though doubles as an adverb meaning "however", and in that role it sits at the end of a clause or sentence. Although can never do this.
- The food was mediocre. The view was worth it, though.
- I'm not sure I agree. Interesting point, though.
It also appears in the fixed comparison as though: She looked at me as though I'd lost my mind. "As although" does not exist.
Where only although works comfortably
Not much, in truth. Although is preferred when the contrasting clause comes first in formal writing, and it carries slightly more weight in a long sentence. But you will not be wrong choosing though.
Even though
Even though strengthens the contrast, marking the fact as surprising or particularly inconvenient: He came in even though he was ill. There is no "even although" — the intensifier attaches only to though. Note also that even if is not the same thing: even though he was ill means he definitely was; even if he was ill leaves it open.
The test
Try moving the word to the end of the sentence, on its own, meaning "however". If that is what you want, only though will do. Otherwise, ask how formal the writing is: a covering letter or a report leans although; an email to a colleague leans though. Either way the sentence is correct.
The comma question
When the although/though clause comes first, put a comma after it: Although the deadline had passed, they accepted the form. When it comes second, the comma is usually optional and often better left out: They accepted the form although the deadline had passed.
Frequently Asked Questions
Can I start a sentence with "Though"?
Yes. "Though the report was late, it was thorough" is standard. Although is a touch more formal in that position, but neither is incorrect.
Is it "even though" or "even although"?
Even though. The intensifier "even" combines only with though, never with although.
What's the difference between "though" and "however" at the end of a sentence?
They mean the same, but though is more casual and sits naturally at the very end: "It's expensive, though." However usually wants a comma and often opens a clause: "It is, however, expensive."