The teacher and woker 和 The teacher and the woker 的动词be 怎样用?

The teacher and worker 老师兼工人,指一个人,所以,谓语用单数第三人称的is.
如 The teacher and worker is at home.
The teacher and the worker 老师和工人,指两个人,所以,谓语用复数的are
如The teacher and the worker are at home.