Canada is the second largest country in the world.
the +序数词+最高级+名词单数
第几最（从第二开始）
Our country is becoming more and more neautiful.
the +比较级，the +比较级
越……就越
My parents don't allow me to hang out with my friends.
建议 允诺 邀 拒绝
非谓语动词，不定式省略to的情况
help sb. （to）do sth.可加to 也可不加to
make/let/have 省略to
【例句】
It's impolite of him not to his seat to the old lady on the bus.
it is +adj. of sb. to do
（修饰人的性格，品质的形容词）+of
it is +adj. for sb.to do（修饰事件）+for
stay behind 留下来
