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/

On French:

• for swearing and Verlan, French slang
• gendered nouns
• A French letter, on the limited French vocabulary of the English
• Comment te dire adieu (with a side-dish of German and Italian).

See also

• Some Portuguese epigrams
• Some Venetian greetings

On the importance of placeholders in achieving fluency:

• A thingamabob about whatchamallit

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

• Learning the lingo