Or, and, most of punctuation

[Anna232]

Should I use a comma after "most of the time" if it is part of a longer sentence? Is my use of commas and either of "speaking" or "conversation" correct?

Most of the time, in speaking/conversation classes we talk about books, movies we want to watch, or have already watched, and our hobbies.

 

[emsr2d2]

Yes, but you need another comma after "classes". That you're specifically talking about conversation classes is extra information.
I'd remove the comma after "watch".

 

[Annabel Lee]

Most of the time, in speaking/conversation classes we talk about books, movies we want to watch, or have already watched, and our hobbies.

The comma before "or have already watched" is very awkward because it occurs in the middle of a larger series whose elements are also separated by commas. It would be better to delete that comma; but if you really want to use it, you could use a semicolon instead of a comma after "books" and "watched" to save the parallelism. A third option is to keep the commas after "books" and "watched" but enclose "or have already watched" in parentheses:

• In speaking/conversation classes, we spend most of the time talking about books, movies we want to watch or have already watched, and our hobbies.
  
  
• In speaking/conversation classes, we spend most of the time talking about books; movies we want to watch, or have already watched; and our hobbies.
  
  
• In speaking/conversation classes, we spend most of the time talking about books, movies we want to watch (or have already watched), and our hobbies.

 

[Anna232]

The comma before "or have already watched" is very awkward because it occurs in the middle of a larger series whose elements are also separated by commas. It would be better to delete that comma; but if you really want to use it, you could use a semicolon instead of a comma after "books" and "watched" to save the parallelism. A third option is to keep the commas after "books" and "watched" but enclose "or have already watched" in parentheses:

• In speaking/conversation classes, we spend most of the time talking about books, movies we want to watch or have already watched, and our hobbies.
  
  
• In speaking/conversation classes, we spend most of the time talking about books; movies we want to watch, or have already watched; and our hobbies.
  
  
• In speaking/conversation classes, we spend most of the time talking about books, movies we want to watch (or have already watched), and our hobbies.

Is the comma used before "or" only when it connects two independent clauses? As in, "Students can choose two optional language moduls, or they can choose one module and a dissertation."

 

[emsr2d2]

Is the comma used before "or" only when it connects two independent clauses, as in no comma here "Students can choose two optional language modules, or they can choose one module and a dissertation"?

I wouldn't use the comma before "or" in that sentence. I would remove "optional" and "they can choose" too. The fact that they can choose them makes them optional.

Students can choose two language modules or one module and a dissertation.

 

[Annabel Lee]

Is the comma used before "or" only when it connects two independent clauses? As in, "Students can choose two optional language moduls, or they can choose one module and a dissertation."

The issue with the comma before "or" in your opening post has nothing to do with "or" not connecting two independent clauses. It is perfectly fine for "or" to follow a comma even when only one independent clause is involved:

• He will buy a cup of tea, a glass of wine, or a bottle of beer. ("or" comes between noun phrases)
• I don't know whether the dog will lie down, sit up, jump, or bark. ("or" comes between verb phrases)
• They would sometimes have lunch in the kitchen, under a tree, or on the roof.
  ("or" comes between prepositional phrases)
• Depending on the time of the day, he can be happy, irritable, or combatitive.
  ("or" comes between adjective phrases)
• He would read the children's book quickly, slowly, or dramatically, depending on his mood.
  ("or" comes between adverb phrases)
• Did he say that he would do it today, that he would come by tomorrow instead, or that he couldn't do it at all?
  ("or" comes between subordinate clauses)

Let's look at your original example again, or the part of it that is problematic with respect to the comma before "or":

• We talk about books, movies we want to watch, or have already watched, and our hobbies.

Following the preposition "about" is a series of noun phrases separated, ultimately, by "and":

• We talk about books, movies, and our hobbies.

The second noun of the series, "movies," is modified by a relative clause containing two verb phrases separated by "or": "we want to watch, or have already watched." Taken in isolation from the broader series of noun phrases, the comma before "or" in that relative clause is perfectly fine; it's optional. But because of the broader series, the comma creates a miscue. The series appears for a moment to be this, which is ungrammatical:

• We talk about books, movies, or have already watched.

Then we reach the comma after "watched," which is followed by "and," and revise our interpretation of the sentence so that it makes sense. You can save the reader this trouble by punctuating in one of the three manners I suggested in post #3.

 

[embertmorton200]

I’ve always found punctuation with “or” and “and” a bit tricky, especially when listing options in a sentence. What helped me was reading examples out loud—if the sentence flows naturally with a comma, it usually reads well. That said, context matters a lot. Sometimes adding or skipping a comma can subtly change the meaning, especially in legal or technical writing.