Passive vioce

He understands the lesson


Present tense

He understands the lesson 
The lesson is understands by him.

Past tense.

He understood the lesson
The lesson was understood by him.

Present progessive

He is understanding the lesson
The lesson is being understood by him.

Past progressive

He was understanding the lesson
The lesson was being understood by him.

Future (will)

He will understand the lesson

The lesson will be understood by him.

Future (be going to)

He is going to understand the lesson

The lesson is going to be understood by him.

Present perfect

He has understood the lesson

The lesson ihas been understood by him.

Past perfect

He had understood the lesson

The lesson had been understood by him.

Modal verbs

He can understand the lesson

The lesson can be understood by him.

He must understand the lesson

The lesson must be understood by him.