Beyoncé 的歌词中 "If I were a boy".如果我是个男孩，就是这样一个句型。
1.I wouldn’t wear a sweater in such hot weather if I were you.
2.If I were you,I would explain to Jack what happened.
3.If I were you, I should get another lawyer.
4.I would think about it very carefully, if I were you.
在虚拟语气中我们通常用：If I were...,I would...句型
Eg：1.If I were you, I would study harder.
2.If I were you, I would stop doing that.
3.If I were you, I would go to the doctor.
1.I would study harder if I were you.
2.I would be more careful if I were you.
3.I wouldn't do that if I were you.
IF + I / HE / SHE / IT + WERE
Eg：1.If I were you, I wouldn't play with fire.
2.If you were me,would you study English or go to the movie?
3.If he were taller, he'd be accepted into the team.
*三.在虚拟语气中，如果要表示“我要是你”，通常是用 If I were you 的，但可以用 If was you 吗？
首先if I was这个句子语法上没错，但并不是虚拟语气了，而是陈述语气;
Eg：1.If I was sick, she would give me medicine that tasted terrible.
2.If I were sick, I wouldn't be here.
有的语法学家认为 If I were you 不能说成 If I was you。比如《朗文英语语法》在14.13.2节就认为在 If I were you / If I were in your position 中不用 was。该书所给例句为：
Eg：If I were you / in your position, I’d accept their offer.
但事实上，日常日常口头表达中也有些英语母语者会用“If I was”.
建议：如果是初学者或作为学生参加考试，以用 If I were you 为宜。
虚拟语气用在与现在事实相反条件句中时，条件从句的谓语用动词的过去式 （be的过去式用were），结果主句的谓语用should(第一人称)或would(第二、三人称)＋动词原形。if 表示“如果”，I “我”，were是"are"的过去式，you”你”，would在这里是"will "的过去式，这里的过去式表示的都是假设，不可能发生的事情。
Eg：1.If I were stronger,I would train for the marathon.
2.If I were an animal,I would be a lion.
3.If I I were in charge,I would give everyone a vacation.
4.If I were you,I would not buy that dress.
5.If I were you,I would study English and find a new job.
6.I'd think twice before buying that car if I were you.