learn english，注意在任何情况下，英语这个单词都是要大写的，所以这个短语是：learn English。过去完成时表示过去的过去，结构是had加动词的过去分词，与现在完成时的结构很相似。造句：He told us he had learned English for just three weeks.他告诉我们他刚刚学了三个星期的英语。
learn的过去式是learned或learnt，现在分词是learning。learn，作及物动词时意为“学习；得知；认识到”，作不及物动词时意为“学习；获悉”。
learnt (过去式) learnt(过去分词)
learned(过去式) learned(过去分词)
例如：He _learned_(learn) honesty from his mother. 他从母亲那里学会诚实。
Such metaphors would have been _learned_(learn) and hard-wired into the brain at a young age.
