Sentence Correction

I'm confused about parallel structure regarding "ing" words . Here's an example:

The phone rings, startling Molly.

OR

The phone rings, which startles Molly.

Because the word, "rings" is used, does that mean "startl-ING" is incorrect? Do both verbs have to end in "s," as in the second sentence. Can someone please explain?

I am not sure if you are asking the parallelism question using correct examples. The sentences you wrote are more suited to discuss modifiers.
There is no parallelism issue with these sentences..

The phone rings, startling ..........
The above is correct usage of a sentence because startling is modifying the verb rings.

The second sentence The phone rings, which startles.... is not right usage.
Which is an adjective modifier which modifies the noun just before the comma. In the above sentence rings is not a noun.

As to parallelism the subjects, verbs and number(plural or singular) should be parallel.

bourne159 wrote:I am not sure if you are asking the parallelism question using correct examples. The sentences you wrote are more suited to discuss modifiers.
There is no parallelism issue with these sentences..

The phone rings, startling ..........
The above is correct usage of a sentence because startling is modifying the verb rings.

The second sentence The phone rings, which startles.... is not right usage.
Which is an adjective modifier which modifies the noun just before the comma. In the above sentence rings is not a noun.

As to parallelism the subjects, verbs and number(plural or singular) should be parallel.

I'm not sure I totally understand. If verbs need to be in parallel, wouldn't rings (a verb) and startling (a verb) need to be the same tense?

What about in the following sentence:

Molly rebuffs Zach's move, citing that her kids should know about their relationship the rest of the world.

Shouldn't rebuffs and citing be the same tense here... meaning that citing should be the same tense as "rebuffs"?