There is no significant difference. The terms are transitions. You can begin either a new sentence or a new paragraph which alludes to what was previously written or spoken by the employment of such words. Consequently, when you write or speak, you can construct your sentences and paragraphs accordingly. Therefore, when you communicate with others, they will regard your communication as something guided by an intelligence. Hence, as you engage in the articulation of your thought, you will make a good impression upon your intended audience. Accordingly, as you employ such terms in your written communication, you will display more erudition than those persons who employ a limited vocabulary, absent the finer nuances of learning. . Notwithstanding however, one should not use any single one of these expressions repeatedly. You see how I begin each paragraph and sentences with a different transitional term? Furthermore, when you write or speak, you want to demonstrate that you have a facility with the language you use. In addition, if you learn to write and speak with measured tones, and write and speak in a sudden rush, as though you are in a hurry, your thoughts and ideas will be taken more seriously. If you have something important to say, slow down your speech rhythm.

please feel free to let me know if there is some of questions that confusing you while learning Chinese : )

Oh,thank you !!! !John Jacob !! You have been of great help to me ! Greatly appreciately !!! : )

Hi Gong, To me, the main difference is tone. "So" is the most commonly used of the above words, isn't fancy, and does not draw attention to itself. "Therefore" is fancier, but still common, both in speech and writing. It's more likely to pop up if someone is making an argument: "This is true, therefore this is true." I don't see "thus" nearly as often as the two above, and I think it's most appropriate use is in an academic paper, or any time you want to sound like a professor. "Accordingly", "consequently", and "hence" can be used as replacements for "so" if you need a greater variety of words. I expect to see them more often in writing than in speech, as they're awkward to say. The above only covers when those words are being used to mean the same thing as "so". The above words can be used in different contexts to mean things very different from "so".