They mean various things and are used in manifold contexts – from fiddling with one's food, or a rubber band because nervousness, or a switch – to using without permission and messing up one's camera, toying with the idea of doing something, or tinkering with,experimenting with, arranging, trying something various ways to see what works best or better figure out how it works, - and having an affair with or making out with someone in a car etc and so on.
In many cases I had the idea that only, for instance, play/ mess with or play/mess around with works, but I've been going through various dictionaries - Webster,Oxford, Cambridge, the Freedictionary, Longman, Collins etc – and there seems to be no difference, with them being used interchangeably and around not changing anything.
Macmillan lists "fool around" as "fool around or fool about [British] or fool with" [one under the other];
fool with something: to handle or play with (something) in a careless way : Don't fool with that gun.
fool around with something: to handle or play with (something) in a careless or foolish way: Don't fool around with that gun.
Cambridge lists fool around with as "fool (around) with" - around being in parentheses, which would suggest it's optional, for all intents and purposes.
To give you a few examples [every two sentences have virtually the same meaning, though one uses "around" and the other doesn't) :
- I can play around with the pictures to make them more eye-catching.
- Play with the design onscreen, moving text and pictures until you get a pleasing arrangement.
- The supervisor played around with our work schedules this week.
- We're playing with a few different solutions to the problem.
- I spent the evening playing around on the piano/computer/Internet.
- Play around with the ingredients if you like.
- He played with many different hairstyles before choosing one he liked.
- I'm not really a painter; I just like to play around with paints.
- I've been playing with designs for my company logo— which one do you like best?
- Hey, don't mess with the thermostat—it needs to stay at 65 degrees.
- Hey, don't mess around with the thermostat—it needs to stay at 65 degrees. [ACTUALLY the very same sentence!]
- Don't mess with the camera.
- Who’s been messing around with my camera?
- We played around with the idea for a while but eventually realized that it just wouldn't work.
- After university, I played with the idea of teaching English in China.
- I was just playing with you when I said I was angry.
- You’re playing around with me. Leave me alone.
- Don't mess around with the ashtray. You'll break it
- Stop playing with the light switch!
- I wish you wouldn't play around with that - you'll break it.
- Please don't play with that crystal vase.
- Did she really ask you about me, or are you fucking around with me?
- Come on, don't fuck with me. Did Tina really ask about me?
My question is does "around" change the meaning of the construction in any way that I should keep in mind? Since dictionaries aren't always completely accurate and reflective of common usage, do you make a distinction between fool/mess/play with and fool/mess/ play around with in you daily speech?