Joke Collection Website - Joke collection - This is a "soft" joke. What's the connotation?

This is a "soft" joke. What's the connotation?

In Chinese class, the teacher writes "soft" on the blackboard and then lets everyone spell it.

The boys all shouted, it's too soft.

The teacher said: boys' pronunciation is not standard, please ask girls to supplement it.

The girls all shouted: It's my day-soft.

The monitor corrected: five nights a day-soft sleeper.

The teacher was impatient and corrected sharply: the correct spelling should be-Friday night I-soft.