Hello there!
The word "grin" would be known To be as a (verb) because the word "verb" means action. They pretty much end in "ing".
For example: (skating,cooking, laughing, playing,choking) all are great examples of the word "verb".
But, not all verbs contain this. The following words that are listed would also be noun to be a "verb".
By using or showing a verb, which I this case, by doing a verb,you can (grin) and you can also (tolerate) something.
Your correct answer is (TRUE).