• If I want to check for understanding i can say...

* did you understand that?

* did you understand what I meant?

* did you understand what she said?

• If I want to show my understanding I can say...

* oh, I understood that

* I know what you meant by that

• If I want to show my lack of understanding I can say...

* sorry i didn't understand

* what did you meant by that?

* I did not understood what she said

hi, and I would like to say thank you for reading this, I would like to apologize in advance if I got any of the answers wrong and good luck ytchifuyuofficial