I have some question about the use of dash (or hyphen?).

1. If I need to indicate a sentence in a sentence so that the main clause gets more clear to the reader, than I can put the sub clause between two dahses.

Am I right?

What is then the difference of using two commas in between the sub clause is placed?

2. I sometimes encounter that some authors use one "dash" just in the begining of the sub clause.

How many dashes should one use? One in the begining, or one in the begining and another at the end?

3. Should there be any space between the dash and the first letter of the sub clause?


the car is green


- the car is green -


I would appreciate if you could answer these questions one by one.

And moreover, I would appreciate if you could provide more information about the dash use, if I have missed something above.

Thank you in advance.


1. When you want to set off a sub-section of your sentence to embed another sentence or phrase, you can use commas, parentheses or dashes. For example: I'll meet you at the Starbucks -- the new one one Elm Street -- after class, okay?

If you are embedding an entire sentence -- and I've seen that used by fiction writers more than other types of writers -- you may be better off with parentheses, which give clearer signals to your readers where the embedded part begins and ends.

2. You can use one dash, but not to set off a sub-section with the rest of the sentence continuing afterwards. You would use that to show an abrupt change of thought -- and by the way, dashes come in two styles: em dash and en dash. (em is — and en is –, and we are talking about the em)

If the entire thing can be lifted from the sentence and the sentence would still make grammatical and logical sense (it would just have less information), then make sure that you have the punctuation of your choice on each side of that sub-section.

3. That's a matter of style. Personally, I prefer to leave a space so the dash doesn't look like an over-zealous hyphen, but some styles guides say to not leave a space. (If you prefer, they say not to leave.)

You can search on this site for em-dash, en-dash, and just dash for more information.
Thank you for the answer!