For what period of time

Asked Apr 06 '15 at 19:42

Active Apr 07 '15 at 06:15

Viewed 33 times

There is a mathematical model. Model can give a forecast for some duration (hours, days, years). But the forecast will not be equally accurate for different periods of time. How should I ask for what period of time the forecast is most accurate?

What is duration, the model can give most accurate forecast.
For whatduration....
What is duration for....

Which of the above is correct? Where can I read about this rule?

edited Apr 07 '15 at 06:15

asked Apr 06 '15 at 19:42

user2760303

It seems like you're not very fluent in English grammar, so maybe our sister site English Language Learners would be a better place for you. – Barmar Apr 06 '15 at 19:48
Which chooses between options, which might be stated or implied. What asks for a specification. You actually use what in the question. – Andrew Leach Apr 06 '15 at 20:19
Thank you. I'll ask on ELL site. But I edited my question. I want to ask how to build the question. – user2760303 Apr 07 '15 at 05:56

For what period of time

0 Answers0