근데(short form of 그런데) used colloquially. 그럼(short form of 그러면) used colloquially. 그렇죠 means "yes, right" honorofic expression or "그렇지" 그래요 means "yes, right" honorofic expression or "그래" 그런데 means "by the way" 그러면 means "and then, if you do so" 그렇지만 means "but, however" 그러나 means "but, however" 그래도 means "even though, nevertheless, nonetheless" 그래서 means "so, therefore, accordingly, consequently, thus" 그러니까 means "so, therefore, accordingly, consequently, thus" 그러는데 means "while doing prementioned action" same meaning to "그러는 중에" 그렇지만 and 그러나 are interchangable 그렇죠 and 그래요 have same meaning. But 그렇죠 has more certain nuance. 그래서 and 그러니까 have same meaning. But 그러니까 is mostly used colloquially.

1. 그렇죠 - Yes. Right. I agree. I see. 2. 근데 - By the way. Anyway. But. 3. 그렇지만 - However. But. Although 4. 그래서 - So, Therefore (So, what do you mean by that? 그래서 무슨 말인데 그게?/ That's why you should listen to me.그래서 내 말을 들으라는 거야.) 5. 그러면 - Then. So. (Let's talk about the next topic then. 그러면 다음 주제에 대해 이야기 해봅시다. ) 6. 그러나 - But, However. 7. 그러니까 - So, Therefore 8. 그래도 - Although, Though (그래도 네가 참아.) 9. 그럼 - Now, Then. (same as 5) 그럼 이렇게 해볼래? 10. 그래요 - That's right. Sure. 11. 그러는데 - 'maybe mistake? don't know what you mean' 왜 그러는데? (Why do you do that?)