【正确答案】This mistake is caused by negative transfer of mother tongue. Consequently, a contrastive analysis of the learner's native language and the target language has and this in turn determines what the learner has to leam and what the teacher has to teach. Since language learners have different mother tongues, the teaching has to vary accordingly. Chunks teaching can also help learners to remove negative transfer, and form a good habit of speaking a second language.