How to say "week" in Japanese

• 週間しゅうかんJLPT N3approx.Common
  nounThe word for a week as a length of time — one week, two weeks, a stay of several weeks. Use it when saying how long something lasts, takes or continues.
  もう２週間しゅうかんたったら帰かえります。↗

  I will be back in another two weeks.
• 週しゅうJLPT N3approx.Common
  noun, noun (suffix)A particular week on the calendar — this week, last week, next week — rather than a seven-day span counted as a duration. For 'for two weeks' or 'within a week', 週間 is the word.
  それはその前まえの週しゅうに買かったものでした。↗

  I had bought it the week before.
• ウィークCommon
  nounA loanword that is seldom the word you want for the seven-day period itself; it appears almost entirely inside fixed borrowings such as Golden Week. In ordinary sentences, 週間 or 週 does the job.

Use 週間 for a week as a duration, 週 for a particular week on the calendar such as this or next week, and leave 「ウィーク」 for fixed loan expressions, since it is seldom an ordinary word for 'week'.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• 週間しゅうかんweek
• 週しゅうweek
• ウィークweek