When should I use the word 'that' between parts of sentences?

Question

What is the correct syntax:

I'm quite sure that your record was successfully created

Or

I'm quite sure your record was successfully created

Answer 1

As Derek mentioned, either is incorrect and neither is wrong, but there might be instances that would prompt someone to include a that.

For example, a that is often inserted is when you want to emphasize that you are paraphrasing a quote. Compare:

(1) Linda said, "Tom has never been to that restaurant."
(2) Linda said Tom has never been to that restaurant.

(notice that (1) and (2) are exactly the same, word-for-word, save for the punctuation)

(3) Linda said that Tom has never been to that restaurant.

If Linda's exact quote was,

"I don't think Tom has ever tried Alice's Restaurant."

then it might be best to include the that, to indicate a paraphrase, rather than a quote. However, as one website indicates, using the word that is not mandated:

Another reason might be for the sake of readability. In some contexts, the extra word might be seen as superfluous, so a writer might leave it out. In other contexts, a sentence may have an unnatural flow without the word, so it might get included.

For example, let's say a friend of ours named Susan was pretending that she has lost one of her shoes, when, in reality, she knew the shoe was still in her car. I might ask:

Who knew Sue knew where her shoe was?

but that reads much like an awkward tongue-twister, particularly since the first four words all rhyme. So, I think I'd be more inclined to say:

Who knew that Sue knew where her shoe was?

even though the first isn't ungrammatical.

Answer 2

Either is acceptable, though the second is more common nowadays. I think the difficulty arises because as well as being used as a conjunction in your example, "that" is the opposite to "this". So you might be asked "Do you want this car?" and reply "No I want that one". Then when you consider that meaning to "that" and place it in your first sentence there's some confusion what the "that" is doing. In common speech "that" is dropped these days

Answer 3

Syntactically, the use of the word that denotes a change in the clause. It is also used to introduce a reported part of the speech, what is most often called Indirect Speech. Colloquially, it has become convention to use a sentence without that because it tends to decrease the ambiguity and the redundancy.

For example, consider conversion of the following sentence to Indirect Speech :

She said, "That was a great meal."

The indirect speech is :

She said that, that was a great meal.

Notice the double use of that. The correct syntax is given above where the first that is followed by a comma. But modern language usage does not require strict adherence to this rule and it has led to the complete omission of that as a clause separator. Both forms (with and without that) are accepted as correct in the current context.

Another point to mention is when to use that as a clause separator. As mentioned in the example above, the presence of more than one adjacent that's in the sentence can make it unseemly and redundant. In such cases, I have found it more comprehensible to replace the that in the speech to it or some related pronoun or by the use of the noun to which that refers to.

Hence, the more modern way to say the above sentence is :

She said that it was a great meal.