We normally think of "though" as a conjunction introducing a contrastive statement, and as the less formal and less forceful equivalent of although and even though. Compare the following: Even though it was suffocatingly hot, she was wearing a thick woollen sweater. Although she was very fond of him, she had no intention of marrying him. We could try to phone her before we go, though we might miss the train if we do. So to sum up, most of the time the word though acts like the word however. For example, "I’m sorry, I can’t stay for lunch. I’ll have a coffee, though"

When you have 'though' at the end of a phrase, it has exactly the same meaning as the word 'but' at the beginning of it. It's sunny today, but it's cold. It's sunny today. It's cold, though. Is John clever? Yes, but he's lazy. Is John clever? Yes. He's lazy, though. This form is neither formal nor informal - it's neutral. It's also very useful, and very common.

If you need any more help please let me know :)