as a conjunction, 'though' introduces a contrast or contradiction to the statement that precedes it. It's similar in function to 'although' or 'even though,' but 'though' is often more informal and can be more versatile in its placement within a sentence.
'Though' can be used to start a sentence, placed in the middle, or even at the end, depending on the structure and style of the sentence.
Though it was raining, they decided to go for a walk.
I really like that dress. It's quite expensive, though.
She doesn't like coffee; she drinks it occasionally, though.
'Though' can often be replaced with 'although' or 'even though,' but the latter two are generally more formal and are usually placed at the beginning of a contrasting clause. When 'though' is used at the end of a sentence, it functions similarly to 'however' or 'but.' This usage is informal and is common in spoken English. A common mistake is overusing 'though' at the end of sentences, which can make speech or writing seem repetitive or informal.