上个星期 and 上周

[bossidy]

Are these interchangeable? Is one used more than the other?

[muyongshi]

They are the same meaning no difference except in usage...former is more often used in spoken and the latter is used more in writing.

[gougou]

former is more often used in spoken and the latter is used more in writing.

Really? I would have said the other way 'round.

[muyongshi]

Well okay I will classify my statement then by saying in Sichuan 上个星期 is said more often in spoken and 上周 is written more as it takes less key strokes...

[skylee]

They are the same meaning no difference except in usage...former is more often used in spoken and the latter is used more in writing.

I agree.

[Jose]

There is also 上个礼拜, which is very colloquial.

To sum up, we can list four ways of saying "last week", from more formal to more informal:

上周

上星期

上个星期

上个礼拜

Note that the more formal expression 上周 is used without a measure word, whereas the informal expression with 礼拜 is nearly always used with the measure word 个. The neutral 星期 is a sort of border case, where the measure word is optional.

[cdn_in_bj]

Well okay I will classify my statement then by saying in Sichuan 上个星期 is said more often in spoken and 上周 is written more as it takes less key strokes...

In Beijing, both are used however I do encounter 上周 more often. As well as 周一, 周二, etc.

[muyongshi]

So in continuation of that here we use 星期一 星期二 more than 周一周二 etc.

I would not list 礼拜 as being very colloquial. It's used but I rarely ever here it. I find more people use it around me when they think I won't understand 周 or 星期.

[cdn_in_bj]

I would not list 礼拜 as being very colloquial. It's used but I rarely ever here it.

It's more commonly used in Taiwan.