Yes; some people also chose to use a semi-colon (;) instead of the comma (,).
Mostly there is, as when you say yes, even though you might not realise, there is always a pause. For example, if in a conversation I was to say yes of course, I would say/write : "Yes, of course!". If I wasn't in a conversation, I would write/say yes, of course(!) but probably starting a new sentence. So yes, you usually do put a comma after the 'yes' :)
It really depends on what the rest of the sentence is. For example, it is correct to say, "I don't know who will be there." In that case, there is no comma before "who". It is also correct to say, "My new neighbors, who have not spoken to me yet, keep letting their dog come into my yard and dig holes." That example does contain a comma before "who".
In general, no, but there are some situations in which using a comma after "but" is correct. If the word "but" is followed by an expression that needs to be set off by commas, then you would put a comma after "but" and another comma after the expression. Here is an example: I was going to say no, but, because you have presented such a persuasive argument, I have decided to allow it. An example of a more typical sentence using "but", where there is a comma before but not after "but", is the first sentence in this answer.
When you are signing a gift card, and you want to say who it's from. Do you write "from, so-and-so"? Or do you omit the comma? Punctuation is not determined by the use of any particular word. It is determined by the structure of the sentence.
5,000,620 (the first comma FROM THE RIGHT says "thousand", but here there are no thousands, so we don't say anything. The second comma FROM THE RIGHT says "million").
Yes when writing stories or other writing pieces you would say: Joey said, "this source is reliable" The comma would be after said and it is the same for he said: He said, " You just learned something new" Hope this helped Source: Like 1st or 2nd grade
last comma before the and is not necessary
???? It depends what you want to say like hello in Portuguese is Ola etc...
You put a comma after the Dear & (person's name) example: Dear Margaret, No offense, but you have huge glasses. Say "None taken." One popular girl at school, Claire That's how you write a friendly letter P.S. Margaret James, really, please change your glasses.
It depends on the context. For example a sentence could say, "I don't like it either." There is no comma.
It is the same as English, you simply say no. To say "No, thanks" for example you would write "No, gracias."
It's impossible to say, since the placement of the comma depends on the rest of the sentence (and is often optional in any event).