I do not understand you do not understand he does not understand we do not understand you do not understand they do not understand
Present continuous
I am not understanding you are not understanding he is not understanding we are not understanding you are not understanding they are not understanding
Preterite
I did not understand you did not understand he did not understand we did not understand you did not understand they did not understand
Preterite continuous
I was not understanding you were not understanding he was not understanding we were not understanding you were not understanding they were not understanding
Present perfect
I have not understood you have not understood he has not understood we have not understood you have not understood they have not understood
Present perfect continuous
I have not been understanding you have not been understanding he has not been understanding we have not been understanding you have not been understanding they have not been understanding
Pluperfect
I had not understood you had not understood he had not understood we had not understood you had not understood they had not understood
Pluperfect continuous
I had not been understanding you had not been understanding he had not been understanding we had not been understanding you had not been understanding they had not been understanding
Future
I will not understand you will not understand he will not understand we will not understand you will not understand they will not understand
Future continuous
I will not be understanding you will not be understanding he will not be understanding we will not be understanding you will not be understanding they will not be understanding
Future perfect
I will not have understood you will not have understood he will not have understood we will not have understood you will not have understood they will not have understood
Future perfect continuous
I will not have been understanding you will not have been understanding he will not have been understanding we will not have been understanding you will not have been understanding they will not have been understanding
Conditional
Present
I would not understand you would not understand he would not understand we would not understand you would not understand they would not understand
Present continuous
I would not be understanding you would not be understanding he would not be understanding we would not be understanding you would not be understanding they would not be understanding
Past
I would not have understood you would not have understood he would not have understood we would not have understood you would not have understood they would not have understood
Past continuous
I would not have been understanding you would not have been understanding he would not have been understanding we would not have been understanding you would not have been understanding they would not have been understanding
Imperative
Imperative
do not understand Let's not understand do not understand