Grammar

"As well as" (which is not a word, it's a phrase made up of three words) simply means "also." So you could substitute "and also" in the sentence: My nephew was naughty at Chinese New Year eve and also the first day of New Year . . .

There are a few minor problems here. One would say: "on the first day of the new year . . . " or, "on New Year's Day" (a recognized holiday in the West, i don't know if it is appropriate to apply that to the Chinese New Year).

Also, you write "my nephew," and then in the second clause, you use the third person singular pronoun "she." A nephew is masculine. You should either use "nephew" and "he," or "niece" (feminine) and "she."

Hi Setanta,
your English is really great,thanks for your explanation.

Thank you--your English is quite good, too.