Confusable Words: Although/but etc.

I’ve sometimes been asked to explain the difference in usage of “but”, “although” and “though”.
First of all, “although” and “though” have the same meaning. The only difference is that “though” tends to be more conversational, whereas “although” can be either conversational and written in formal emails or letters.
For example:
“I had a great time in London, though/although the weather wasn’t very good.”
“”We will make every effort to despatch the order this week, although it depends on our supplier’s availability.”

“But” sounds more final.
For example:
A: “As I will be in New York on Tuesday, I would like to drop by your office to meet you.”
B: “I would very much like that, but unfortunately I won’t be in New York on Tuesday.”

Compare that to this example:
A: “Let’s meet at the restaurant of The Four Seasons tomorrow at 7pm.”
B: “That sounds fine, although they often have no space at such short notice. I’ll call them to check and then let you know.”

Here is another example to contrast the usage:
“I’d love to join you this evening, but unfortunately I have to get up early tomorrow, so I’d better get back to my hotel.”
“I’d love to join you this evening, although I have to get up early tomorrow, so I’d better only stay for a short while.”

So, as “but” sounds more final, it can be used to show a stronger feeling of dissatisfaction.
For example, “I’ll drink red wine, but I’d prefer white,” sounds more dissatisfied than, “I’ll drink red wine, though I’d prefer white.”

A similar word is “however”. It can be used in place of either “but” or “although/though”. One key difference is that “however” cannot be used to combine two sentences; it either starts a sentence, or ends it. If it starts a sentence, it is followed by a comma; and if it ends a sentence, it is preceded by a comma.
For example:
“I would very much like that. However, I won’t be in New York on Tuesday, unfortunately.”
“I would very much like that. I won’t be in New York on Tuesday, however.”
Personally, I think it sounds better at the start of the sentence, to prepare the listener for the bad news.
If it starts a sentence, it can be delayed, and placed after the verb or modal: “I won’t, however, be in New York on Tuesday, unfortunately.”

Other similar words or phrases that must be used in new sentences (not as conjunctions) are “in spite of this”, “nevertheless”, “regardless”.
Examples: “They are not satisfied with one or two of the conditions. “In spite of this, I think they will sign the contract.”
These expressions can also be used in conjunction with “but” or “though/although” in one sentence as in “”They are not satisfied with one or two of the conditions, but in spite of this, I think they will sign the contract.” It doesn’t really add much to the sentence; it just adds a little more certainty.