Phrases that use いい加減 (e.g. いい加減にしろ！) have often been a mystery to me. According to one dictionary, at least, there were so many possible meanings this phrase could have:
- irresponsible; perfunctory; careless;
- lukewarm; half-baked; halfhearted; vague;
- reasonable; moderate;
- considerably; quite; rather; pretty;
But which meaning makes the most sense in general usage?
It wasn’t until just recently that I’ve noticed that when 加減 is used in the phrase: 手加減をしない (when used as a way to explain the phrase: 容赦ない,) it appears to be used to indicate “not [going] easy on someone” or “not [being] reasonable“.
When used in this way, the phrase いい加減にしろ！ seems to make more sense in that the particle に is helping to indicate that the speaker using the phrase wants the listener to “make [it] reasonable!”
In this way, narrowing down the context of how and when a phrase is used can begin to help with piecing together language puzzles such as いい加減.