～ついでに: meaning and how to use it (JLPT N3 grammar)

At a glance

～ついでに means "while you're at it" or "since I'm already doing X". You do a main action and use it as a chance to also do something extra.

Verb (dictionary form) + ついでに、～
Verb (た-form) + ついでに、～
Noun + の + ついでに、～

買かい物ものに行いくついでに、銀行ぎんこうに寄よります。 Since I'm going shopping anyway, I'll stop by the bank.

ついでに attaches to the plain form of a verb or to an action noun with の. Politeness goes at the end of the sentence.

Attaches to	Form	Example	Meaning
Verb (dictionary form)	行いく → 行いくついでに	駅えきに行いくついでに	when I go to the station
Verb (た-form)	行いった → 行いったついでに	駅えきに行いったついでに	when I went to the station
Noun + の	散歩さんぽ → 散歩さんぽのついでに	散歩さんぽのついでに	while out for a walk
On its own	ついでに、～	ついでに、これもお願ねがいします。	While you're at it, please do this too.

The dictionary form usually describes the occasion as a plan or on the way. The た-form usually means "having done X (and being there)".