Is this correct usage?

[sw001]

Is this correct usage?

The judge ruled against the plaintiff.

Another one - whats the correct Idiomatic Usage of "Significant"?
You have significant contributions to this project.
You have significantly contributed to this project.

Thanks

[RonPurewal]

Is this correct usage?

The judge ruled against the plaintiff.

It's fine.
In fact, I can't even guess what you think is wrong. What do you think is wrong?

[RonPurewal]

You have significant contributions to this project.

This sentence is wrong, but not for any reason related to idioms——it's just nonsense.

A "contribution" is not something that you can have (in the present tense).
You can make contributions to something, in various ways. But, once you've made those contributions ... you've made them. It's inappropriate to say that you "have" them.

As a pretty close analogy—You can make a lot of comments.
Afterward, I can write "You have made many comments." I can't write "You have many comments."

By contrast, consider sentences in which the present tense "have" does work.
E.g.,
You have strong opinions.
(= you hold these opinions now. They're your opinions; you have them.)
Sophia and Jake have 6 children.
Etc.

[RonPurewal]

You have significantly contributed to this project.

While not technically wrong, this one is weird. Generally you'll see "significantly" after "contributed".
Word order isn't tested on the GMAT, though, so this is a non-concern. (You could be tested on placing "significantly" as close as possible to "contributed"——since it's an adverb describing "contributed"——but that's an issue of close placement, not of word order.)

[sw001]

Thanks Ron for your replies and for explaining the "contribution" part!!

[RonPurewal]

Sure.