How do we know when to use which, when they convey the same meaning?
The dictionaries say this:
- Pick – choose (someone or something) from a number of alternatives.
- Select – to choose (someone or something) from a group
- Choose – to decide that a particular person or thing is the one that you want
Examples:
- I'm doing a test and I don't know which answer to [choose,select,pick]. {Why choose?}
- I have [chosen, selected, picked] this color because it looks good on you. {Why chosen?}
- You need to [pick, select, choose] three numbers from 10 to 99. {Why pick?}
- I have [selected, chosen, picked] two students who will attend the festival today. {Why selected?}
Edit.
- I can never select/choose/pick the right answer in this test. {all the three are possible}
Best Answer
The three words are almost completely interchangeable.
I read your first couple of examples without realising you'd provided what you thought was the answer, and I didn't pick the same options you did!
For the first one (answers in a test) I'd lean towards "select".
For the second one (colours which look good on you) I'd use either "picked" or "chose" (NB past simple rather than past perfect... we very rarely use past perfect).
For numbers I agree with "pick"; this is just because there is a common phrase "pick a number from {x} to {y}"
For students who will attend the festival, I really can't choose which one would be best.
Thoughts on what differences there may be:
"Select" is generally only used where there are finite options. If you can only have red, green or blue, you could select one of them; but if you can have any RGB colour from 0-0-0 to 255-255-255 then "choose" or "pick" would likely be more appropriate.
"Select" also works well in the imperative, probably as it sounds slightly more formal than "choose" or "pick". Hence "Select from the following options" works well.
"Select" also works well with tickboxes (or checkboxes for Americans or IT people), whether they are on paper forms or on your computer screen.
"Pick" is quite informal. It works well with complaining: "Hurry up and pick one already!". It's also the most appropriate when you are physically taking an item, due to the (probably) related phrase "to pick something up".
"Choose", as per your definition, implies selecting what you want. e.g. "You can choose from hang-gliding, rock climbing or karting" works well; "Choose all the words that are about size" doesn't so much (that should be "Select").
All thoughts above are based on my experience as a native British English speaker.