Run quickly or quickly run is correct?

Answer 1

Correct English can have the adverb before or after the verb. So, you have to look at the sentence and ask questions about sense, ease and ambiguity. For example, if one were to say:

He ran quickly.

This implies he ran quickly as opposed to slowly. However, when one says:

He quickly ran.

This implies that he ran instead of walking, or it could mean that he was doing something else and then suddenly, very quickly, he began running.

You just have to look at the situation and ask yourself which sounds better, which makes the most sense in the manner you intend, or what flows with the greatest ease..

If it is preceded by the word "to", this is a different story. If you had a sentence that was:

He started to quickly run.

This is actually what is called a "split infinitive". An infinitive is simply a verb with the word "to" preceding it: to walk, to see, to hear. You want to keep the "to" and the verb together and not split them apart, hence the term "split infinite".

Just remember that any time you have the word "to" and a verb following, don't put anything between them. That is a good rule of thumb and easier than remembering the definition of a split infinitive.