Here's how to tell which it is:
* Plural noun: If it's referring to multiple rushes (like a type of plant or a sudden movement), then it's a plural noun.
* Example: The rushes by the river were swaying in the wind.
* Third-person singular present tense verb: If it's describing an action that someone or something is doing, then it's a verb.
* Example: He rushes to the store every morning.
To determine the correct form, you need to look at the sentence it's used in and understand the context.