Hi, I'm outlining my thoughts so that people can understand my thought process and hopefully guide me if I get any misconceptions along the way.
I saw a table a Native speaker made for a video, which was very helpful:
| Foo | みたい | らしい | そう |
|---|---|---|---|
| Impressions from what we can see | 🟢 | ||
| Judging a situation | 🟢 | 🟢 | |
| Information gained from rumors/others | 🟢 | 🟢 | |
| Making comparisons | 🟢 |
Additionally, she also said that っぽい can be used for any situation that uses mitai or rashii. This seems to track – you might say that an adult acts childishly at times using either:
たまには、先生子供みたいな行動をします。
たまには、先生子供っぽくな行動をします。
Or, do the same with らしい：
先生はいつも大人らしい、きびしいな人。
先生はいつも大人っぽく、きびしいな人。
However, I don't really get the nuance between these two. Is there a reason why sometimes Japanese people say one or the other? I understand that っぽい is less formal, but other than that, I don't see any other nuance difference.
by SparklesMcSpeedstar