So adverbs are modifiers, which means that they are used to describe another word in the sentence. And in the case of adverbs, they describe verbs. Similarly, adjectives describe nouns. So if you want to use an adverb in a sentence it's really important to make sure that it's describing a verb and not a noun. I'll give you an example. In this sentence, ran is our verb, or it's our action.
And our actor, or our subject, is he. Which means that fast is our adverb. It's the descriptive word that is explaining how he ran. One thing that's important to note about adverbs is that they can be a sign of weak writing. And so if you're trying to punch up your writing it's important to go through your document and circle all of the adverbs and see if perhaps you could use a stronger verb. Often times we need a modifier to give more information about a verb because the verb wasn't very strong to begin with. So this is a perfect sentence. He ran fast. That's a little bit of a weak adverb.
It doesn't give us a lot of information. Maybe it's a sign that we needed a stronger verb, like say, "he sprinted". Then we know that he's running really fast and we don't need an adverb here because sprinted is such a strong word. Or we might say, "he jogged". And "he jogged" indicates that maybe he's running a little more leisurely. So again, just keep in mind when you use adverbs make sure that they're not a sign of a weak verb.