可能有很多同学认为托福考试只有在阅读和写作中会考语法，其实托福口语一样会考察语法知识。而且托福口语考试对语法的考察难度更大，因为考生在答题时是没有时间考虑语法规则的使用的，要把对语法的使用变成一种潜意识的“习惯”。很多考生考完语法后自我感觉良好，可是拿到成绩单后却大跌眼镜，殊不知都是这些隐形的杀手在作怪。

杀手一号：主谓一致

以下是学生课上答题的答案，大家能看出来这个同学的答案哪里错了?

Imagine that a guy drive along the high way where have a lot of billboards advertising cars. One billboard advertise a car called panther. This guy drive by, but he don’t notice that. If you ask him later to name an animal that start with letter “P”. Instead of saying pig, he say panther. He have no conscious memory about the billboard, but the billboard had an effect on him.

正确答案是：

Imagine that a guy driveS along the high way where ‚HAS a lot of billboards advertising cars. One billboardƒ advertiseS a car called panther. This guy ④driveS by, but he⑤ DOESN’T notice that. If you ask him later to name an animal that ⑥startS with letter “P”. Instead of saying pig, he ⑦sayS panther. He ⑧ HAS no conscious memory about the billboard, but the billboard had an effect on him.

错误原因：

主语是第三人称时，谓语还是原型，并没有变形。其实，除了主语是第三人称时谓语要做第三人称单数的变形，当主语是名词性从句，动词不定式，和动名词时，谓语也要用第三人称单数。

杀手二号：时态一致

过去时的使用是时态使用中较为简单的一种。可是，要做到在答题时需要使用过去时的时候都记得要使用过去时却没那么容易。同学在答题时会把注意力集中到语言的组织上，无暇顾及时态，所以常常会出现时态的混用。请大家看看下面这位同学的答案有什么问题：

I went out to a movie yesterday, and I watch Smurfs 2. After the movie, I had dinner with friends.

这个同学描述的是昨天做的事情。前面记得用过去时，说着说着，变成了一般现在时，到最后又变回了过去时。

正确答案：

I went out to a movie yesterday, and I watchED Smurfs 2. After the movie, I had dinner with friends.

杀手三号：人称一致

人称一致问题是同学在答托福Task5的时候惯犯的一个错误。Task5是学生困难和解决题，一男一女进行对话。对话中一个同学叙述自己遇到的问题，另外一个同学提出解决方案，题目要求是复述学生的困难和解决方案等。学生答题时一会儿用she,一会儿用he, 无法自拔。我们来看看下面这个同学是怎么答题的：