第一种句式是将否定性时间状语提前的倒装句式.
not until +时间状语从句＋倒装后的主句
例句 Not until he saw the toy did the baby stop crying.
第二种句式是强调句,强调时间状语.
It is not until +时间状语从句＋that+主句
例句 It was not until he saw the toy that the baby stoped crying.
第一种句式是将否定性时间状语提前的倒装句式.
not until +时间状语从句＋倒装后的主句
例句 Not until he saw the toy did the baby stop crying.
第二种句式是强调句,强调时间状语.
It is not until +时间状语从句＋that+主句
例句 It was not until he saw the toy that the baby stoped crying.