per week/every week

[Kacy.H]

Hi, everyone. I feel it is wrong to use 'every week' or 'weekly'. But I don't know why. Could you explain?

The amount of time spent doing housework first fell significantly from 50 to 15 hours per week/every week/weekly between 1920 and 1980.

 

[JulianStuart]

It's the standard way of presenting such quantitative information in that kind of (scientific) context - like "miles per hour" or "pounds per square inch", etc. The other two may be fine in conversation but not here.

 

[Kacy.H]

The other two may be fine in conversation but not here.

Thanks, Julian. But do you think even in conversation, the meaning would be wrong if I use 'weekly'.

'Weekly' means once a week. Does it sound like the amount of time fell from 50 to 15 hours once a week?

 

[Egmont]

"Per week" is used instead of "every week" because "per week" is a rate, while "every week" is a statement about how regularly the activity is performed. A person in 2000 might not do 15 hours of housework every week. He or she might alternate between weeks of 5 hours of housework and weeks of 25 hours of housework, for example. That's not 15 hours every week - in fact, it isn't 15 hours in any week - but it's still a rate of 15 hours per week.

"Weekly" means the same as "every week," so it's also wrong here.

 

[Kacy.H]

He or she might alternate between weeks of 5 hours of housework and weeks of 25 hours of housework, for example. That's not 15 hours every week - in fact, it isn't 15 hours in any week - but it's still a rate of 15 hours per week.

Thanks, I don't understand the bold, so I don't know how the rate of 15 hours per week is calculated. Could you rephrase the bold, please?

 

[JulianStuart]

Thanks, Julian. But do you think even in conversation, the meaning would be wrong if I use 'weekly'.

'Weekly' means once a week. Does it sound like the amount of time fell from 50 to 15 hours once a week?

Weekly can also be used with a less restricted meaning : the weekly output of the brewery is 5,000 gallons; the brewery prduces 5,000 gallons each (or every) meek; the output is 5,000 gallons per week.