Is there a general rule that allows to replace "noun + that + verb" with "noun + ing-form of verb"?

Consider this sentence:

Metal physical properties are key traits that determine the quality of products.

Can this be written as:

Metal physical properties are key traits determining the quality of products.

The second sentence already has a main verb and key traits is it an object? I am confused.

I would like to know in general when can "that" be omitted? If this question has already been asked I can't find it through the search.


1 Answer 1


[1] Metal physical properties are key traits [that determine the quality of products].

[2] Metal physical properties are key traits [determining the quality of products].

It's not a matter of omitting "that" in your second example. Though the bracketed clauses in [1] and [2] are semantically similar, they belong to different categories, the former a relative clause, the latter an ing participial clause.

In [2] "key traits determining the quality of products" is a noun phrase functioning not as object but as predicative complement of "be". The head word is "traits" and the participial clause is its modifier.

  • Thank you for the clarification. So what the general rule is that "that" can be omitted in a participial clause? I never heard about participial clause I will have to read up on it. Nov 29, 2021 at 10:39
  • 1
    "That" does not introduce non-finite clauses such as participial ones, so the question of when "that" can be omitted in such clauses does not arise.
    – BillJ
    Nov 29, 2021 at 16:11
  • Yes. That optionally introduces tensed complement clauses, like I think (that) he did it. Such clauses always have a tensed verb. Participial clauses, on the other hand, don't have tensed verbs -- participles aren't tensed. Nov 29, 2021 at 16:26

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.