八岁学英语可以用 "eight-year-old learning Engpsh" 来表达。这个表达方式来源于英文的年龄表达方式。在英文中，人的年龄通常是在"age" 后面加上数字来表示的，例如 "eight years old" 表示八岁。在这种情况下，"eight-year-old" 是一个形容词，用来修饰名词 "learning Engpsh"。
下面是一些例句：
My eight-year-old son is learning Engpsh.
我八岁的儿子在学英语。
She is an eight-year-old girl who is learning Engpsh.
她是一个八岁的女孩，正在学英语。
I started learning Engpsh when I was eight years old.
我八岁的时候就开始学英语了。
下面是一些例句：
My eight-year-old son is learning Engpsh.
我八岁的儿子在学英语。
She is an eight-year-old girl who is learning Engpsh.
她是一个八岁的女孩，正在学英语。
I started learning Engpsh when I was eight years old.
我八岁的时候就开始学英语了。