if the meaning is "great effort", then "high effort" is just not correct
In English it is better to say "that is a big effort"
Yes, in Vietnamese we say "Đó là một nỗ lực lớn." That sentence (Đó là một nỗ lực cao) is said by Duo (not a Vietnamese person).
I don't really understand what this sentence means. Can anyone help shed some light for me?
I think it means "That is a lot of/much effort".
For example, your boss tells you: "we have to do a report on the sales to small shops on the last two years".
You, knowing that this will need to manually review every sale in the last two years, warn him: "that is a high effort".
Maybe this is an attempt to translate the English idiom "that is a tall order", implying that the task requires an unreasonable amount of effort.
Why is it 'sự nỗ lực' in a very similar exercise in this module?
From my observation seems like Vietnamese sometimes omit "sự", certainly for language enconomy. I think it works for some words but not for others.
I try many times and I always hear "Nó là một nỗ lực cao".