'Follow up on' versus 'follow up'

[Gray]

Which is correct?

I could follow up on the answers.

I could follow up the answers.
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First lesson - English, not english. I, not i. ~A student of English

[Mister Micawber]

.
I could follow up on the answers. Your second sentence needs, e.g. an adverbial: I could follow up the answers with a new set of questions.
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Native English teacher at Mister Micawber's

[Gray]

But I still have a doubt --

1)
"I could follow up the answers with a new set of questions."

Why do we need an adverbial here? For example, if I substitute the verb "read" --
"I could read the answers", would I need an adverbial there too?

May be, there is some confusion.

2)
"I am posting a message so that I could follow up the answers."

Do we need an adverbial in this context too?
_________________
First lesson - English, not english. I, not i. ~A student of English

[Cerberus™]

[Gray]

[Cerberus™]

Regrettably I must disagree with you again. The verb "to follow [something] up with [something]" is special only in the type of adjunct that is required: "with" is not often required with a verb.

Even so, it is not that special: take, for example, "to put up with [something/someone]", where it is also required.

Note that both "put" and "follow" may be used without both "up" and "with": then they just have different meanings.

Some general statements:
- As to what complements or adjuncts are required with a specific verb, even this may differ depending on context.
- Most verbs require one or more complements in most contexts, though by no means in all. When in doubt about a possible complement or adjunct, add it. Rarely will you go wrong by adding too much; but often by adding too little. Too much might look a bit stuffed or redundant, but it won't break the grammar or make the sentence unintelligible.
- I cannot think of any more specific rule of thumb that applies to all verbs, most of this is context and idiom.