That is because…”与“That is why…”之间的不同：
“That is because…”指原因或理由。
“That is why…”则指由于各种原因所造成的后果。
例如：
He did not see the film last night. That is because he had to help his little sister with her homework.昨天晚上他没有去看电影， 那是因为他得帮助他的妹妹做作业。(第一句话说明结果， 第二句话说明原因)
He had seen the film before. That is why he did not see it last night.他以前曾看过那部电影， 因此他昨天晚上没有去看。(第一句话说明原因， 第二句话说明结果)
