Here are some examples:
Noun:
* The line at the grocery store was long. (Line refers to a queue of people)
* The artist drew a line on the paper. (Line refers to a mark made with a pen or pencil)
* He recited his lines perfectly. (Line refers to a part of a play or script)
Verb:
* The children lined up for the ice cream truck. (Line means to arrange in a row)
* He lined his pockets with money. (Line means to fill something)
* The soldiers lined the streets for the parade. (Line means to stand in a row along something)
To determine whether "line" is a noun or verb in a sentence, consider its function within the sentence. If it acts as the subject or object, it's likely a noun. If it describes an action, it's likely a verb.