Could you explain to me which is right, please.
1. How much time you do you spend on the Internet? -About 5 hours. -That is too many!(or too much)
2.How much do you weigh? – 80 kilos. – That`s too much! (or too many)
Thanks a lot.
"Many" is for countable things. "Much" for uncountable.
The sticking point in your questions is whether you are thinking of the "time" or the "hours." It's too much time, but too many hours. It's too much weight, but too many pounds.
"Much" is used with uncountable nouns.
Time is uncountable, so we use "much".
The number of apples in a bag are countable, so we use "many".
How many stars are there in the galaxy? Countable.
How much distance is there between the two stars? Uncountable.
How much do you weight is countable - use "much", not "many".
Countable/uncountable is the standard grammatical explanation. But here is a simple rule that learners can use to choose between much and many. Use many with plural nouns and much with singular. The rule also works with less and fewer. Use less with singular nouns and fewer with plural.
I just ran across this rule in William Safire's On Language, a collection of his NY Times columns from the 1970's. I think it works all the time. At least I haven't been able to think of any exception.
Thank you very much for your answer.