"They are" or "that they are"? [duplicate]

It's clear they are honest.

vs.

It's clear that they are honest.

Is there a difference? Is one more correct than the other?

Solution 1:

In your sentence

It's clear that they are honest.

that is used as a conjunction to introduce the clause that serves as the complement of the predicative adjective clear.

This is one instance when that can be omitted [there are other cases of omissibility of that but I will only deal with the particular case about which you are asking]:

Adjective + that-clause
We use be + adjective + that-clause to express opinions and feelings. Some adjectives commonly used in this way are sure, certain, right, important, afraid, pleased, sorry, surprised, worried [and we can add clear in this category]. We can omit that with no change in meaning:

• It’s important (that) we look at the problem in more detail. (Cambridge)

The omission of that is still controversial nowadays, especially in writing. Many advocate that omitting that is informal, but we are seeing a shift in use even in formal speech or written texts. This site recommends:

As a general rule, if the sentence feels just as good without the that, if no ambiguity results from its omission, if the sentence is more efficient or elegant without it, then we can safely omit the that.

In your case both versions of the sentence are correct, but since there is no ambiguity and the sentence definitely feels less heavy without that, I would use

It's clear they are honest.

without any worry that the meaning is changed.