Learn English – “Have you ever worked in a …” vs. “Have you ever been working in a …”

The first answer is correct because the first speaker, let's call him Bob, wants to know something about the second speaker's life experience, whom we shall call Alice. For example,

Bob: Have you ever lived in Madrid?
Alice: No, never!

Bob wants to know whether Alice at some point in her life lived in Madrid. Maybe she has Spanish relatives, maybe she is a bohemian and has lived in several different cities in her lifetime, whatever the pretext, Bob wants to know about Madrid. At this stage, he is not interested in knowing "when" she lived there, only if she did. He must, therefore, be fairly certain that Alice is not currently living in Madrid.

Now, Bob asks Alice a second question, using the PRESENT PERFECT again.

Bob: Have you ever worked in a factory?
Alice: No, never!

The structure of the question is the same, Bob is asking about a specific situation that Alice may or may not have experienced at any time up to ‘now’. Alice replies that she has never worked in a factory, it is an experience which she didn't have in the PAST. Had she replied differently

Alice: Yes, I have! (= I have worked in a factory)

This would mean that Alice, at a specific point in her life, worked in a factory. But Bob wouldn't know ‘when’, so he might inquire further with any one of the following questions, using the SIMPLE PAST:

Bob: When was that?
– How long did you work there?
– Where did you work?
– What was the name of the factory? etc.

On the other hand, if Alice is currently working in a factory, she might reply:

– Actually yes, I do work in a factory
– Actually, I am a factory worker.
– Didn't you already know? I work in a factory.
– Funny you ask me that, I'm actually working in a factory at this moment.

In which case, Bob could dig deeper, using the PRESENT PERFECT CONTINOUS construction, and ask Alice

How long have you been working there?

The PPC is often used in questions asking about the duration of an action or situation that is perceived to be temporary in nature, it is preferred when the speaker wants to emphasize the continuation of an activity, but the Present Perfect can also be used if the speaker interprets the situation or act as being more permanent.

Bob: “How long have you worked there?”
Alice: ”Ever since I left school.”
– “Since I was 16.”
– “For about twenty years.”