Despite two well-written and well-taken, good questions, my answers are very opinionated. I have based this theory on my own experiences.

I know two factors are at play in this site but mostly they’re physical ‘tough’ and ‘nice’. When the verb introduces the topic, we have the verb introducing the subject (or topic). In your examples these are both plural nouns so “are” seems to come naturally. How come nouns are surrounded by quotation marks, since “topic” refers to the concept rather than the plurality of nouns? With this logic applied to plants, we should

use “is”: “Eatable flowers” is

a subject. This doesn’t look great and is certainly not best practice, but could be valid given the above logic!

Second factor is the one you specifically asked about. Typically, after a word like “subject” or “topic”, we must use the singular verb form since we are now referring to the singular word “subject” or “topic”. What subject is? I immediately said “comes up” each time. I’m a jive. Voicing what you say out loud, I know there are you, too. I think the plural form sounds out of place as my ear is concentrating on “subject” rather than “eatable flowers” or “tools.”

I know I found the right thing!

This page is from the Blue Book of Grammar and Punctuation. For students who want to learn grammar and punctuation, consider reading the book Blue Book of Grammar and Punctuation.

Often the pronoun who, this, or which is the subject of a verb in the middle of a sentence. What makes the pronouns who, that, and which into singular or plural according to the noun directly in front of them.

If the noun is singular, use a singular verb. Even a plural verb will make sense. If it is a plural verb, use plural verb.

In your sentence, “Eatable

flowers are a subject that comes up in almost all cooking classes eventually and I am a big fan of them.”

Why do people say I influenced you?