要不是 (yàobushì) is almost the same as "如果不是⋯⋯ "， and it may followed by "的话," meaning "if it were not for" or "without."

要不是 她帮忙，我们不可能这么快找到这个地方。We couldn't have found this place without her help.
要不是 你说你想吃，我不会做这个菜的。I wouldn't have made this dish if you hadn't said that you want to eat.
要不是 因为他是你朋友，我是不会帮他的。I wouldn't have helped him if it were not for him being a friend with you.
要不是 你们迟到的话，我们早就到了。We would have gotten here earlier if it were not for you being late.
要不是 你刚才说错话，他是不会生气的。He wouldn't be mad if it were not for something wrong you just said.

See also

Sources and further reading