Help me with this question and explanin please :) Tom IS or IS BEING very naughty these days. How is correct?
If you were to characterise Tom as naughty, you would say Tom is naughty.
If it is a particular case or a singular incident, you would say "Tom is being naughty today/these days" or "He was being naughty yesterday/those days".
Tom is being naughty.
Tom is behaving in a naughty manner.
Tom is naughty.
It is in Tom's nature to behave in a naughty manner. That's how Tom is.
"These days" means "lately". So "these days" works well with is being. Tom is behaving in a naughty manner lately.
With is, however, the meaning imparted by "these days" would run counter to the idea that it is in Tom's nature to behave in this manner. Rather, it would be something like "Tom has undergone a change of mood or personality; he has been acting naughty lately".