The word “that” can be omitted from your copy “99 percent of the time,” a PR Daily commenter declared last week.

Is that advice accurate?

“Whether you say ‘I think you are wrong’ or ‘I think that you are wrong’ is partly a matter of idiom but mostly a matter of preference,” author Bill Bryson explains in his book, Bryson’s Dictionary of Troublesome Words.

Bryson does offer some guidelines. Three words require “that,” he says.

1. Assert
2. Contend
3. Maintain

And two words, which often precede “that,” do not require it.

1. Say
2. Think

Ultimately, you should kill “that” from your prose whenever possible—a point with which Bryson seems to agree.

“On the whole,” he writes, “it is better to dispense with ‘that’ when it isn’t necessary.”