didnt完整形式did not没有;未;Did not 和 didnt 通用因为didnt 是简化版的did not， 不过在正式的书写是不建议用任何的简化
例句
We did not even make enough money to cover the cost of the food.
我们挣的钱甚至无法糊口
He did not look too pleased when I told him.
我告诉他时，他似乎不是很高兴。
He did not return her love.
他没有回报她的爱
