Cindy Cendana , an Indonesian beauty influencer, just wanted to know if any of her followers had been to the Japanese city of Himeji . So she posted the question — “Hand’s up, who’s been to #Himeji, Japan?” — on Instagram, along with a photo of herself in a blue dress.

Ms. Cendana could have anticipated a number of comments — restaurant recommendations, tips about visiting the feudal castle there — but certainly not this one: “If you put an apostrophe after ‘hand,’ it either means ‘hand is’ or something that belongs to the hand. In this case, it should be ‘hands’ as you’re referring to multiple hands.” (The post no longer appears in Ms. Cendana’s feed.)

She wrote in a text message that she still remembers when she first saw the comment in February: “I was surprised, but happy at the same time because I had my clumsiness corrected for me.”