How to say "indefinitely" in Japanese

• いつまでもJLPT N3approx.Common
  adverbCovers 'indefinitely' as 'forever, for good, as long as one likes' — a duration with no set end. This is the common word, as in staying somewhere as long as one likes or waiting forever.
  私はいつまでも彼かれの名なを覚おぼえている。↗

  I still bear his name in mind.
• いついつまでも
  expressionA less common doubled form of いつまでも, glossed 'indefinitely; for a long time'. For the 'forever, for good' sense of 'indefinitely', いつまでも is the common word.

For 'indefinitely' as 'forever, for good, as long as one likes', use the common 「いつまでも」; 「いついつまでも」, a less common doubled form, covers the 'for a long time' sense.

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

• いつまでもforever
• いついつまでもindefinitely