commas

[Francois]

I see your point navi.
I for one would say:
I didn't close the door so that the cat should go out (=> meaning a)
I didn't close the door, so that the cat should go out
(=> meaning b)

FRC

[Casiopea]

Originally Posted by navi tasan

4-I didn't close the door for the cat to be able to go out.

a-I did close the door, but for something else (to keep the dog out)
b-In order for the cat to be able to go out, I didn't close the door.

If I understand your reply correctly, you are saying that 4 can mean a. There, we have no problem. The question is whether 4 can mean b. And if we want it to mean b, should we use a comma?

First of all, we need a sentence that has meaning. Sentence 4- is semantically odd. I don't know what it means. Sorry. It's 'for the cat to go out' that has me confused. Consider,

5) I didn't do it for the cat (i.e. for the benefit of the cat). A comma is not needed. In this case, 5) carries the same meaning as a-,

5) I didn't close the door for the (benefit of the) cat.
a- I closed the door for another reason.

6) I didn't close the door because I want the cat to go out. A comma is not needed. In this case, 'because I want the cat to go out' answers the question,

Q: Why didn't you close the door?
A: I didn't closed the door 6) because I want the cat to go out.

Sentence 6) and b- carry the same meaning,

6) I didn't close the door because I want the cat to go out.
b- In order for the cat to be able to go out, I didn't close the door.

As for the original sentence,

4-I didn't close the door for the cat to be able to go out.

It's awkward with 'for' because it means,

I didn't close the door for the benefit of the cat to be able to get out. :?

Try,

I didn't do it because.... (i.e. for this reason). Seems to me you're using 'for' where you should be using 'because'. :D

All the best,

[navi tasan]

Good explanation. Thanks a lot.
All the best to you too.