We were learning the seasons, so はる、なつ、あき、ふゆ。 I had some prior knowledge, but not enough, and honestly looking back it was more of a brain fart. After hearing fall was あき, the teacher asked if anyone knew winter, to which I blurted out, そら!
Now, you might not get why this is as embarrassing as it was, but there was one other student there who knew, and he still reminds me of it to this day.
I don’t get it. 
Well, if someone says “hold me”, they probably don’t mean a hug.
It also shows up in the dictionary. 
I was once talking to my Japanese friend and I wanted to encourage her to ask a guy about something. However I mixed up the words “to ask” and “to answer” so I was standing there telling her she should “answer him!” 
She was a bit confused but she got what I meant. I only noticed my mistake much later then i remembered this situation…
Ten years here (fifteen since I started studying Japanese) and I still say 転倒本末 if I’m not paying attention, lol. (the correct would be 本末転倒)
「求めっている」じゃなくて「求めている」だと思います。Sorry, it was just bugging me a little bit…
ありがたいです。
Any corrections are welcome.
Once I accidentally said I was 十一歳 instead of 二十一歳. In comparison this is not nearly as bad haha. Though I was a bit tired and my brain was working on like one brain cell, but still, we should probably aim after being able to speak somewhat comprehensible Japanese even in operating-on-one-brain-cell moments.
I think my last mildly funny, but not exactly tragic blunder was when my teacher asked me about family, to which I replied that “I don’t have any siblings” with a sad face.
Well, parents are family, too 
.
I was looking a a suitcase and told the clerk やさいです instead of やすい。
The amount of times ive mixed up 座る and 触る…
Good that it was only in speech, not in action 
This is so perfect 
This is me but the opposite. At my first teaching job in Japan, I’d say “gochisosama deshita” to all my co-workers when I saw them in the hallway, and again when they left for the day. This went on for months (MONTHS) until I listened closely to the other ALT I worked with saying “otsukara” and I was like “wtf did you just say?”
The Japanese teachers either didn’t notice, or they were too kind to say anything. I fear the latter. At least it made for a good running joke.
If anything, they were probably shocked you thanked them for their hard work! I don’t think it would be offensive in any way… nnless you told them the food was garbage and they stink. I promise this mistake isn’t as embarrassing as me trying to write kanji on a whiteboard in front of all my kooky middle school kids. They love to laugh at me and my speaking too
You reminded me of another one.
A Japanese fried of mine said ヤサオ to me and right after asked if I knew what it means, since it’s not a regular textbook word. (It’s an abbreviation of 優しい男)
I did know what it means, so I said yes, and then said in all glory やさい男. (In my head it was やさしい. Only in my head, tho.)
They burst laughing so hard, lol
Would that be by any chance “couch potato”? 
I used 人参 instead of 人間 literally yesterday.
Also I just burned 人間 in my reviews just now, what a coincidence
That reminds me of a podcast that I listened to you. A foreigner dating a Japanese woman went to her house to meet her parents. After short introductions, they went into the living room where there was a couch.
The foreigner turned to face his girlfriend’s mother and asked politely, "触ってもいいですか？”