1.Today is my birthday.
否：Today is not my birthday.
疑：Is today your birthday?
2.Yesterday was Tom's birthday.
否：Yesterday was not Tom's birthday.
疑:Was yesterday Tom's birthday?
3.I bought a bicycle last year.
否：I did not buy a bicycle last year.
疑:Did you buy a bicycle last year.
4.He plays basketball every Tuesday.
否：He does not play basketball every Tuesday.
疑:Does he play basketball every Tuesday?