I do not understand the grammatical differences between "though" and "although".
Can we use them interchangeably?
Although they may seem confusing, most of the time, 'although' and 'though' mean the same thing. 'Although' might be slightly more formal, though. In my first sentence, I can easily change 'although' to 'though' ('Though they may seem confusing ...'). In my second sentence, I can't use 'although'.This shows that 'though' has at least one extra use - at the end of a clause, by itself. Other uses include the phrases 'even though' and 'as though'. If you remember one word to use in your speaking or writing, remember and use 'though' - it is used in more ways, and is (slightly) more common.