快速记忆：

grand极重要的+father祖先=grandfather

vt. 不受新规定限制例句：

Darwin was the grandfather of the theory of evolution.

My grandfather used to drink a cup of green tea before he went to bed.

我的祖父过去常常在睡觉前喝一杯绿茶。

I love chatting with my grandfather on Sunday morning.