I find that I’ve written quite a few jocular posts about language learning—here are some faves.

Most remarkably, how not to learn Japanese:

• That is the snake that bit my foot

On Chinese:

• two classic stories from Paul Kratochvil (here and here), as well as
• struggling with some arcane pinyin, and
• Changing language

Intriguing shopfront https://stephenjones.blog/2017/09/10/shabi/

For swearing and Verlan in French:

• French slang

On the limited French vocabulary of the English:

• A French letter

See also

• Some Portuguese epigrams
• Some Venetian greetings

And here David Sedaris covers various languages, including Japanese and German:

• Learning the lingo