Hi there,

I tried looking up the rules for using 'that' in a sentence. I understand it's mainly used to combine two clauses. I don't understand the specific rules though; a lot of sentences look like they'd work fine with 'which' as well..

For example:

I'd buy the music which has the most features. (this sentence borders on fine, although I am sure it's not really correct)

I'd buy the music player that has the most features.
I'd buy the music player with the most features.

I'd really appreciate it if someone could explain the rules for using 'that'.

I tried looking it up on various websites, but the technical words didn't really help hit the point home. Please explain it without going technical (I don't really understand what a noun clause, an adverb clause or an adjective clause means. I tried looking up the definition but those were accompanied with more technical words that confused me further. Emotion: wink )

Thank you.

ps One more question: I get confused b/w the usage of FOR and OF. The sentence highlighted in yellow up there ends with 'rules for using that'. Why can't we say: rules OF saying that. Some clarity on this subject would be appreciated as well.
S.P.I.I tried looking up the rules for using 'that' in a sentence.
I don't think you're going to find "the rules for using 'that' in a sentence". There are quite a few separate uses of the word 'that', some of which are nearly impossible to explain "without going technical"! The best anyone can do under those circumstances within the limits of a forum post is to give a few examples of the most common types.

1. "said that" type.
Larry said that he was tired.
Gina knew that Frankie had lied.
We believe that we will succeed.

2. "thing that" type.
The thing that bothers me most is his attitude.
I lost the shirt that I bought last summer.
The man that won the race yesterday was from Los Angeles.

3. "fact that" type.
The fact that Paul is fat has nothing to do with his intelligence.
Everyone on the committee discounted the claim that Mr. Smith had cheated on his income tax.
The belief that devils can invade the human mind is not part of modern psychology.

4. "that thing" type.
That coat is red, but this coat is blue.
I don't want that donut; I want the other one.
That is right. That is wrong.

5. "that much" type.
We'll have to economize; we don't have that much money left.
You may like her, but I don't think she is that pretty.
I can't imagine why you're perspiring. It's not that hot in here.

Some people advocate that the word "that" can be removed, and should be in about 90% of the cases where it has been used.

It is interesting to remove them entirely and see the result. If something need be there instead, usualy there is a better word than "that".

"Which", can sometimes be a better choice, among others.

For and of.

The rule for saying that is.
The rules of saying that are.
 CalifJim's reply was promoted to an answer.