The following are the main differences and usages of the words ‘understand, see, get, grasp, and comprehend’.

Understand
It is used to express a general meaning.

• Do you understand me?

• I don’t understand politics.

See
It is a general expression like 'understand', used informally and colloquially.

• I see what you mean.

• I don’t see why it is important.

Get
It has a general meaning like 'see' and is used in informal language.

• She didn’t get the joke.

• He is a liar – do you get?

Grasp
It means to fully understand something, implying clear perception.

• The significance of this development can not be fully grasped now.

Comprehend
It expresses a complete understanding of something like 'grasp' and is used in formal or written language - often used in negative sentences.

• They failed to comprehend the scale of the danger.

• I simply couldn’t comprehend what had happened.

Take in
It is used in the sense of fully understanding and assimilating something.

• The painting is too abstract to take in at a glance.

Follow
It is generally used as to understand the speaker.

• His argument is difficult to follow.

Fathom
It is used to understand the explanation or reason for something.

• He spent years to fathom the mysteries of life.

Apprehend
It often appears in ancient texts.

• It was difficult for him to apprehend the situation.