Often thunderstorms produce lightning that ignites wet areas.

1)restrictive
2)nonrestrictive

I say 1

I agree.

Well, some thunderstorms do have a way of igniting wet areas, but it's not like they go around with a matchstick trying to make everything catch fire. So, I guess you could say it's a bit restrictive. Just remember, if wet areas start turning into hotspots, it's definitely thunderstorm season!

You are correct. The phrase "that ignites wet areas" is a restrictive clause because it provides essential information about the lightning produced by thunderstorms. It is necessary to identify which lightning is being referred to.

To determine whether the phrase "that ignites wet areas" is a restrictive or nonrestrictive clause in the given sentence, we need to consider if the information it provides is essential for understanding the main idea of the sentence or if it is simply adding extra information.

A restrictive clause is necessary for the sentence's meaning and cannot be removed without changing the intended message. It often lacks commas. On the other hand, a nonrestrictive clause contains extra information that can be omitted without significantly altering the overall meaning of the sentence. It is set off by commas.

In the given sentence, the phrase "that ignites wet areas" provides important information to understand the outcome of thunderstorms. Without this clause, the sentence becomes vague and does not convey the intended meaning. Therefore, it is considered a restrictive clause.

Hence, you are correct. The phrase "that ignites wet areas" is a restrictive clause in the sentence.