Explanation
Do something while or after completing another action; 'while', 'by the way'.
Formation
Verb (dictionary or た-form) + ついでに, Noun + の + ついでに, or Verb-て form + いる + ついでに
Detailed explanation
The ～ついでに grammar point is used to express doing something 'on the occasion of' another action. It can mean 'while you're at it', 'by the way', or 'in passing'.
Examples
Kaimono ni iku tsuide ni, yuubinkyoku de tegami wo dashimashou.
Let's drop off a letter at the post office while going shopping.
Toshokan de hon wo karita tsuide ni, tomodachi ni aimashita.
I met my friend while borrowing a book from the library.
Nihon ni kita tsuide ni, yuumei na kankouchi wo otozuretai desu.
While visiting Japan, I'd like to see some famous tourist spots.
Eigakan ni itta tsuide ni, shinsaku no posutaa wo mimashita.
While going to the movie theater, I saw a poster for a new film.
Practice
Grammar content sourced from hanabira.org.