interrogatives - How did you like the concert?

How did you like the concert? (Cambridge dictionary)

When there are interrogative words, inversions, gaps (I don’t know if there are gaps in this example), it’s just like getting through a long tunnel, in a foggy morning, on a calm highway. Next is my flash on the construction. Would you check what is wrong? First, I’d like to change the sentence into an in situ question to make my saying better.

You liked the concert how?

From this, I suppose that ‘the concert how’ is a small clause or verbless clause. I mean ‘you were pleasant that [the concert (is) how]?’ From the word, liked, the speaker expects the listener would have enjoyed the concert, yet he likes to know ‘the concert was how’ for the listener. So the replying words would be approving, descriptive words for the concert.

Answer

You liked the concert how? sounds very unnatural to a typical American. In most cases, the question would immediately identify the questioner as a non-native English speaker. How did you like the concert? is the correct and typical way to ask the question.

However, there is a case in which You liked the concert how? can be correct in conversational American English.

Person 1: How did you like the concert?

Person 2: I liked it. I plugged my ears and closed my eyes.

Person 1: You liked the concert how? (The vocal intonation heavily emphasizes how.)

Person 1 is essentially saying, I can't believe you enjoyed the concert like that. Can you confirm that you really meant what I heard? Person 2 has already provided some information. Person 1 is expressing disbelief or astonishment, and asking for clarification. You liked the concert how? is not the initial inquiry.

Here are some more examples:

The concert started when? (After hearing the concert started 3 hours late.)

The concert was held where? (After hearing the concert for a popular group was held in a too-small venue.)

These examples are exceptions, and are probably only used in informal, conversational English.