Are they interchangeable, or is 昨週 an old way to say it, and not used as much any more?


If anybody knows any kind of nuances or differences, such as where one would be more appropriate, it would be interesting to know. Thank you very much!

3 Answers 3


昨週 is in a dictionary, but I have never heard the word. While 昨週レストランに友だちと行った is not necessarily incorrect, I think 先週 is the most natural word for any instance. It's also confirmed by search results in Google:

  • 先週 24,800,000 results
  • 昨週 11,200 results

There are no difference between 先週 and 昨週 in meaning. 昨週 does not seem to be old-fashioned. It's just a rarely-used word.


昨 mean (the) last. 昨日 means 'yesterday,' 昨週 means 'last week.' 昨週 and 先週 is the same thing, but we seldom hear the former (昨週) these days. In written form, it looks natural. In colloquial form, it sounds too stylish and awkward. We say 昨年、昨夏、昨晩、likewise. 昨年 is common as well as 去年。 昨夏、昨晩 sound stylish and a bit outdated as compared with 去年の夏、昨日の夜 to me. But that's my personal opinion.


昨週, reads saku-shuu, is a noun. It's simply not used in the language, even if it can be translated as "last week" as 先週, reads sen-shuu, which is an adverb. The kanji 昨 is used to say "yesterday" though, in the word 昨日, reads kinou. When you are talking about somebody you pay your respect to and/or you like to be more polite to the person your are speaking to, you read 昨日 as saku-jitsu.

  • 3
    "先週 ... is an adverb" >> この辞書の例文集には「先週の」「先週は」「先週も」「先週より」が出てきますが・・。(ところで 「昨週」を辞書で調べると、「今週の前の週。先週 。」と書かれています)
    – chocolate
    Dec 29, 2015 at 15:06
  • Well, what I meant is that 先週 in the Japanese language is used as an English adverb would be used in the English language. In some books or dictionaries they are called adverbial nouns which doesn't help much to understand the difference. The problem, as usual, is the impossibility to translate to English directly as you need two words in English to talk about the week before the current, "last" which can be an adjective, an adverb or a noun based on the context and "week", a noun.
    – nattoman
    Dec 29, 2015 at 15:23
  • 3
    "昨週 is a noun" "先週 is an adverb" >> What's your source? The 昨週 in 昨週レストランに友だちと行った is used adverbially, and you can rephrase it as 先週レストランに行った. And you can say「昨週の」「昨週から」 as well as 「先週の」「先週から」, using 昨週/先週 as a noun followed by a case particle. So both 先週 and 昨週 are adverbial nouns, and can be used as an English adverb would be used in the English language, no?
    – chocolate
    Dec 29, 2015 at 15:53

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .