English idiom for learning a skill by observing someone else doing it

I've had this silly obsession for a while: I can't seem to find a proper phrase in English that is as expressive and 'colorful' as the idiom in my native language that describes learning a new skill by watching someone else doing it, without being actively/intentionally trained how to do it.

In my native language (Romanian) we have a fura meserie — it literally means 'to steal someone's trade'.

Is there an English equivalent? This question has been bugging me a bit more that it should.

Solution 1:

In the business context the phrase often used to convey this meaning is:

Work shadowing

the activity of spending time with someone who is doing a particular job so that you can learn how to do it: You need to get quality work experience or do some work shadowing. - Cambridge.

Where the word shadow expresses the idea that you follow the person you are learning from like a shadow to observe what they are doing.

Job shadowing and work shadowing are two phrases used interchangeably:

Job shadowing allows the observer to see and understand the nuances of a particular job. The job shadowing employee is able to observe how the employee does the job, the key deliverables expected from the job, and the employees with whom the job interacts.

-- from the article: Job Shadowing Is Effective On-the-Job Training at thebalance.com

Solution 2:

Monkey see, monkey do is colorful whose main meaning is the imitation of another person's actions simply by observation and copying but with no understanding.

Copying the behaviour of another without reason or understanding.

(Collins)

Since it is used for rote imitation, bypassing the understanding process, it is often applied to children or, in a pejorative way, to adults.

So, it is not a compliment. Although it can be used humorously to apply to a given situation.

"Monkey see, monkey do" is a traditional phrase used for commenting on someone's (often a child's) tendency to imitate whatever he or she sees someone else doing. Eric Partridge, "A Dictionary of Catch Phrases American and British," calls it a Canadian and U.S. catchphrase originating about 1925, "by c. 1950, also English, but . . . [used] rather to describe the learning of a a [sic] process, which, although performed thereafter with reasonable competence, is never actually understood."

(The Phrase Finder)

But it can also mean, more generally, to learn something by observation, as in:

Over twenty years ago, a team of scientists, led by Giacomo Rizzolatti at the University of Parma, discovered special brain cells, called mirror neurons, in monkeys. These cells appeared to be activated both when the monkey did something itself and when the monkey simply watched another monkey do the same thing.

For the construction of the sentence, see Why Do We Say "Monkey See, Monkey Do"? at Behind the Dictionary.

Again, the phrase is usually pejorative, but it can be applied humorously.

Solution 3:

There is an English idiom, to learn by osmosis.

This is, as you describe, to pick something up simply by observation and practice in the presence of an expert.

The idiom is most frequently encountered when discussing the learning of a language. Simply being around native speakers results in learning by osmosis. Note that it does not imply that the learning is strictly accurate.

Solution 4:

There is a phrase

watch and learn

which is commonly said to the observer by the doer before they commence work.

It can also be used as a taunt when showing off to someone who has been unsuccessfully trying to do something.