difference between stop by and stop on?

[Yolanda]

English Language Tests, Intermediate level

ESL/EFL Test #235 "Phrasal verbs and traveling", question 7

On their way to the city, the newlyweds thought they would ......... an old hangout for a quick drink because it was on the way.

(a) stop on
(b) stop out
(c) stop by
(d) stop down

English Language Tests, Intermediate level

ESL/EFL Test #235 "Phrasal verbs and traveling", answer 7

On their way to the city, the newlyweds thought they would stop by an old hangout for a quick drink because it was on the way.

Correct answer: (c) stop by

Your answer was: incorrect
On their way to the city, the newlyweds thought they would stop on an old hangout for a quick drink because it was on the way.
_________________________

What?s the difference between stop by and stop on? What is their meaning?

Thank you
Yolanda

[Snezana]

Yolanda,

I'll try to clarify this for you:

stop by means to visit a person or place for a short time, usually when you are going somewhere else (e.g. I thought I might stop by on my way home as I haven't seen you for ages.). Phrasals stop in, stop off and stop at have similar meaning.
stop down in the field of photography means: (on a camera) to reduce (the diaphragm opening of a lens).
stop outmeans 1. to withdraw temporarily from school (e.g. Most of the students who stop out eventually return to get their degrees.
and 2. British & Australian, informal: to stay out at night and not come home, especially when other people are expecting you to come home (e.g. If you're going to stop out will you let me know?)

I couldn't find stop on as a phrasal verb in any dictionary, but it can be found like this: First Stop on the Road to Empire - as a headline in a newspaper.

All these are from Cambridge Dictionaries Online and Dictionary.com

I hope to have helped you.

Snezana