How many percent do you understand for her lecture?

I'm not quite sure what you are trying to say, maybe, "What percent of her lecture did you understand?"

Hi

I would say that you only use percent when there is a number in front of it ...

- I only understood about five percent of that lecture

Alternatively, the word is 'percentage' and it is non-count (i.e. you would use 'what') ...

- What percentage of her lecture would you say you understood?

More simply, I'd probably say ...

- How much of her l

It is not right to use 'many' or 'much' with percentage. It is that both these words deal with some amount or number. But percentage is actually a value out of 100. It is like asking how much/many is the ratio of cats to dogs. So it is better to use ' what percentage' instead of using either of those two words.

It is what I want to know. Today I spoke out it without any thinking. I think I learned to use "what" when using "percent", not "how many". Thank you for your teaching, Enoon

Thank you so much for your kind explanation.

Thank you for your explanation, Pathfinder1992