In short, "ever" cannot be used to make an assertion, but rather to ask a question, or an embedded question (wh-clause).
For instance
He is asking me whether I have ever been to New York.
Have I ever been to New York? I don't think so. I have never been to New York.
The wh-clause "whether I have ever been to New York" cannot be used by itself; it is dependent on another clause.
Also note that we can make a statement with "ever", if it is negative. This is based on the principle that "never" can be regarded as a condensation of "not ever"
I have not ever been to New York.
Finally, structures like "have I ever been ..." are possible, if they express irony or emotive emphasis. For instance, "Boy, have I ever been cheated!"
This could somehow apply to New York.
A: Have you been to New York?
B: Have I ever been to new York! I spent three weeks there just last year and actively explored the city for something like ten hours a day.
Different meaning. have never eaten means you've never tried this fruit, you don't even know the taste. When never eat means you don't eat them, it is not your habit, I won't see avocados in your hands. But notice that if you don't eat them, it doesn't imply you've never eaten them. Maybe you used to eat them before, but then stopped.
Best Answer
*I never been have a good English.
And I don't believe the Op wants to say: "I have never been good at English"
Instead, if I'm not mistaken, the op wishes to say:
There's something about "a good English" that tells me the OP is talking about the level of his or her English. In Italian it is correct to say: "Ha un buon inglese"( *that person has a good English), but in order to be grammatical and sound idiomatic, we have to say: "His (or her) English is good."
To change that sentence into the present perfect we must say: "So far his English has been good."
In the present perfect, the negative adverb, never, is usually between the auxiliary— has —and the main verb in the past participle, in this case; been. My grammar books indicate that this is the correct word order.
Present perfect with ever, never, already, yet
However, I am aware that never can also precede the auxiliary and the main verb.
To prove this, Google books reports 18,100,000 results for never has been, whereas a mighty 186,000,000 results are produced for has never been construction.