in front of :在物体外面的前面.
in the front of ：在物体里面的前面.
a lot of = lots of (修饰可数与不可数名词）
many :只可修饰可数名词
much :只可修饰不可数名词
be good at doing sth :擅长做某事
be good with sb :对某人好
help sb (to) do sth :帮助某人做某事
help each other :互相帮助
when I grow up :当我长大以后
tell sb to do sth :告诉某人做某事
tell sb about sth :告诉某人有关的事
ask sb to do sth :叫某人做某事
buy sth for sb :为某人买某物
例：I buy a white sweater for my mother .
buy sth from sb :从某人处买来某物
例：I buy a white sweater from clothes store .
sell sth to sb :卖某物给某人