Although - though (but)

Although and though are conjunctions. Though can also be used as an adverb.

The only real difference between the two conjunctions although and though is the 'feel' which a native speaker of English has for his own language, and the general sounds and rhythms of her speech. It is a free stylistic choice, although there is a tendency to prefer the longer although in formal English. Though is commoner in informal speech. Only though can be used as an adverb (at the end of a clause, meaning roughly 'however'). This is not common in academic English.

There are two common problems in the use of both though and although. The first is more common among non-native speakers . The second may afflict anyone - and does.

• When you use either of them to introduce a clause, you are saying that one thing is different from another . (Most students can ignore the extremely careful language of OED, which defines it as: "An adversative particle expressing that relation of two opposed facts or circumstances (actual or hypothetical) in which the one is inadequate to prevent the other, and therefore both concur, contrary to what might be expected.") Because the conjunction is enough for that idea of opposition, you should never use [al]though followed, at the beginning of the Main Clause, by but.
• Native and non-native speakers alike can make the typing mistake that produces thought, through or even thoorough instead of though. We trust that your proof-reading is better than that.