A SC question confused me,please help me!

Hi wanghewei
To make two or more verbs parallel, they must all be the SAME type of verb. They can be linking verbs or action verbs, but not some of each.

Examples of Linking verbs: to be, seem, look, feel, STAY ... ----> (followed by adjective)
He is strong - He is Billy - He feels good ("well" is incorrect because it is an adverb) - Mango tastes delicious - He stayed calm
(Hint: usually linking verbs can be replaced by "verb to be" in terms of meaning)

Example of Action verbs: (the rest of the verbs that describe an action)
He teaches Math - He looked at me - He tasted the soup - He ran away

Back to your question:


in Sentence 1: the linking verb "is" can't be put in parallel to the action verb "teach"
in Sentence 2: both are linking verbs "is" & "stays"

Check this link to know more about the examples of linking verbs (you don't need to memorize): https://grammar.yourdictionary.com/parts-of-speech/verbs/linking-verbs.html