They usually at home 是正确的吗

They are usually at home.

不正确，They are usually at home.

不对
They are usually at home .

少谓语 they are usually at home

当然不对啦！大姐呀，你这句话没有Be动词，知道吗？对了，嘿嘿，才怪呢！
They usually stay at home.（他们经常呆在家里。）

补充一点：
home可作名词，也可作副词。在这句话中作为名词，所以前面有at。如果作副词，前面就不用介词，例如：go home而不是go to home。