Yes indeed a child can learn any language but it usually starts with the spoken word
English is a lingua franca used by 2/3 of the world from basic pidgin upwards. At pidgin level English is easily picked up by most non native speakers. To graduate towards tertiary level fluency takes 20 years immersion. A language has 4 phases Listening - speaking - reading - writing. Each has levels of fluency

I think my OP must be separated from what we define as English style as opposed to unambiguous meaning as in a court of law. I believe we need to view this from the position of logical argument in the classical sense perhaps with a boolean approach in mind, so we can get away from opinionation

Its important to know how to answer "Did you or did you not kill that man?"

or perhaps

"I put it to you that you killed that man, did you not - yes or no?"

No - could imply - yes i did
Yes could imply yes i did not but may be mis understood as yes I did kill

You see how tricky this can get - and we are not even trying yet

So we need some logical rules here from those skilled in the arts pls

Robin

Honourable contributors, pls do not take offense when I say that my OP was addressed to UK English speakers. It is widely understood that US English usage can differ widely from our own meanings in the UK. The English language has been described as the most difficult language in the World. It can take 20 years to become fluent from a constant educated immersion from say age 4 supported by a reading list of some 100 books from classical literature Victorian to modern.

For example Tim's response above I believe shows how the meaning of aspoken sentence can change depending on which word is emphasised.

"Have you stopped beating your wife,"

Try putting stress on each of the six words in turn

Indeed if your really want to get screwed up, try stressing 2 out of 6 , 3 oo 6 , 4 oo 6

Anyone understand or not understand my question :-{}