JLPT N1Spoken and written

がてらwhile out doing; on the same trip

You go out for one thing and fit a second into the same trip.

私わたしは散さん歩ぽがてら、図と書しょ館かんに予よ約やくした本ほんを受うけ取とりに行いった。

While out for a walk, I went to the library to pick up a book I had reserved.

How to form it

Noun for an outing + がてら

No の in between: 散さん歩ぽがてら, not 散さん歩ぽのがてら.

With a verb

Verb stem (ます-form without ます) + がてら

届とどけます becomes 届とどけがてら.

Before it: An outing or an errand: 散さん歩ぽ, 買かい物もの, ドライブ, 花はな見み. 散さん歩ぽがてら is the one you'll hear most. Or what a trip doubles as: 運うん動どうがてら駅えきまで歩あるく, walking to the station partly for the exercise.
After it: Usually going somewhere: 行いく, 寄よる, 訪たずねる, 〜てくる.
Said about: One person or one group doing both things.
Where you'll meet it: Conversation among adults, blogs, essays, travel writing, a shop inviting you to drop in. It sounds grown-up and a little old-fashioned; everyday speech more often has ついでに.

In use

母ははは買かい物ものがてら、市し役やく所しょで住じゅう民みん票ひょうを取とってきた。

While out shopping, my mother stopped at city hall to get a copy of her residence record.

姉あねは書しょ類るいを届とどけがてら、以い前ぜんの同どう僚りょうに挨あい拶さつしてきた。

My sister delivered some documents and used the occasion to greet her former colleagues.

散さん歩ぽがてら、駅えきまで送おくっていくよ。

I'll walk you to the station and make a stroll of it.

One walk, two reasons: seeing you off, and getting a stroll.

お散さん歩ぽがてら、ぜひお立たち寄よりください。

Do drop in while you're out for a walk.

A café or a gallery, inviting people in.

It isn't a general "while"

Two things going on at the same moment take ながら.

Not said: 音おん楽がくを聞ききがてら、宿しゅく題だいをした。

(I did my homework while listening to music.)

Here it's 音おん楽がくを聞ききながら.

Close neighbours

ついでにN3

The everyday choice, and a wider one: any chance to add an extra job, at home too. After a noun it takes の.

洗せん濯たくのついでに、カーテンも洗あらった。

While I was doing the laundry, I washed the curtains too.

かたがたN1

Formal and courteous, for visits and letters: you come to thank someone, apologize or pay your respects, and do something else with it.

お礼れいかたがた、ご挨あい拶さつに伺うかがいました。

I have come to pay my respects, and to thank you as well.

かたわらN1

Years, not one trip: a second activity kept up alongside your main work.

彼かれは会かい社しゃに勤つとめるかたわら、小しょう説せつを書かいている。

He writes novels alongside his job at a company.

を兼ねてN1

One trip, event or thing planned to serve two purposes. Everyday as well as written.

散さん歩ぽを兼かねて、図と書しょ館かんまで歩あるいて本ほんを返かえしに行いった。

I walked to the library to return a book, and made a stroll of it.

Check yourself

1Which one fits?

テレビを見み（　　）、晩ばんご飯はんを食たべた。

Choose an answer to see why.

2Which sentence sounds natural?

Choose an answer to see why.

More detail

Few verbs come before it: mostly ones for going to see, sending off or delivering. 見みがてら, 送おくりがてら, 届とどけがてら, 訪たずねがてら.

More sentences

私わたしたちは花はな見みがてら、城しろ跡あとまで足あしを延のばした。

While out viewing the cherry blossoms, we went a little farther to the castle ruins.

健けん太たはジョギングがてら、河か川せん敷じきの工こう事じの様よう子すを見みてきた。

While out jogging, Kenta went to see how the construction work by the river was progressing.

祖そ父ふは町まちの様よう子すを見みがてら、昔むかしの知ち人じんを訪たずねた。

Grandfather visited an old acquaintance while taking the opportunity to see how the town was doing.

兄あには友ゆう人じんを訪たずねがてら、近ちかくの美び術じゅつ館かんにも立たち寄よった。

While visiting a friend, my older brother also stopped by a nearby art museum.

叔父おじは墓はか参まいりがてら、故ふる郷さとの友ゆう人じんを訪たずねた。

While visiting the family grave, my uncle also visited a friend in his hometown.