语言学习者在语言习得过程中普遍使用着两个学习策略: a 采用了母语习得中的学习策略:归纳概括,又常常过渡归纳概括。如当他们获知被动语态的构成后,他们会造出The math problem was worked out by James himself的正确句子,也会造出 Our plan for a short trip was maked yesterday的错误句子,就是因为他们过度归纳概括了被动语态规则:所有过去分词的构成都是在动词后加ed。类似的过度归纳概括错误比比皆是,数不胜数。b 迁移自身已有的母语规则来指导二语学习,又时常负迁移。如他们会发现They often sit in the classroom与母语规则相似,就会自觉地或不自觉地造出He often sit in his own room的错误句子来,甚至在许多与母语规则差异甚大的地方也使用母语的规则来遣词造句。语言学家们把学生使用这些学习策略引起的学习行为称之为学习者在构建自己的内部语言大纲。学生更倾向于在运用语言时遵循自己的内部大纲。这个现象在被控制的语言运用中不太明显。在不被控制的语境中,更自由、更自然、更注意语义时,这种现象就十分明显。
1、复习must、can’t、might。教师拿着一张画着一个外国人的图片问全体同学:Is he Chinese? (Ss: No, impossible.) He can’t be Chinese. He must be English or American. Is he American or English? (Ss hesitate.) I’m not sure,either. Englishmen and American men look quite the same. He might be American or he might be English. I just now used the modal verbs: must, can’t and might. When should we use must? (Ss: When we are very sure about something or somebody.) When should we use can’t? (Ss: When we are very sure about something or somebody that isn’t …) When should we use might? (Ss: When we are nor very sure about somebody or something.)
2、引入must have done、can’t have done、might have done。教师对前排一学生耳语,那位学生立刻走出教室并关上了门。教师问全体同学:Where is Hong Guo? Has he gone to Beijing? (Ss: No, impossible. He was here a moment ago.) He can’t have gone to Beijing. He was here a moment ago. Can you tell me where he might have gone? (Ss: He must have gone to the teachers’ office/He might have gone to the toilet.) You gave perfect answers. And you correctly used the modal verbs: must have done and might have done. When should we use must have done? (Ss: When we are very sure about something that happened or somebody who did …) When should we use can’t have done? (Ss: When we are very sure about something that didn’t happen or somebody who didn’t do …) When should we use might have done? (Ss: When we are nor very sure about something that happened or somebody who did …)
3、学生看图叙述故事,要求在叙述时使用must have done、can’t have done和might have done。故事的开头是这样的:架子上的蛋糕不见了。谁拿走了它?是高个儿的约翰还是矮个儿的汤姆?学生以四人小组为单位编故事。他们在故事中自然地、正确地使用了must have done、can’t have done和might have done的句子结构。如:
John must have taken the cake because he was tall enough to get it.
Tom can’t have taken the cake because he was too short to get it.
Tom might have taken the cake because he might have used a ladder to get it.
John can’t have taken the cake because he is always a good boy.
在教师精妙设计的语境中,学生从已有的知识经验(must、can’t、might的用法)中理解了新知识(must have done、can’t have done、might have done)的结构和用途,并在教师安排的活动中学会了正确运用它们。与此同时,他们的观察能力、理解能力、归纳能力、想象能力、解决生活中实际问题的能力和创造性地构件英语句子的能力同时得到训练,达到模块设计的培养学生学科能力和创新能力相结合的功能目标。