What is the difference between に伴って and と共に？

Question

Can somebody explain to me the difference between と共{とも}に and に伴{ともな}って？ I believe that sometimes they can be used interchangeably, but not always. Moreover, their basic meanings also seem to differ. As a matter of fact, it seems to me that に伴って is similar to に従{したが}って、while と共に is more similar to 一緒{いっしょ}に。

Answer 1

Both of them have the meaning of "showing the change of certain situations while another situation is still happening" with some slight differences:

1) 「〜に伴{ともな}って」 (original form: 伴{ともな}う = to accompany) means: "accompanied with" or "in association to something", which can be preceded by either a noun or a verb.

例 (Example):

人口の増加に伴って、たくさんの住宅が建てられる。

Many houses are constructed in association to the increase in population.

2) 「と共{とも}に」used to show that something also occurs together at the same time with a change of certain condition. The entire sentence doesn't require to show a state of progress, and is somewhat equivalent to 「一緒に」or 「同時に」.

例 (Example):

皆さんと共に快適な道づくりを進めます。

With everyone we will go forward with a pleasant road construction.

Both forms above are often compared with 「〜に従{したが}って」and 「〜につれて」which has similar nuances but a slightly different usage:

• 「〜に従{したが}って」means "according to something", which states that the actions described in respective clauses happen in parallel (i.e. the second clause happens following the first clause).

例 (Example):

上司の命令に従って、手紙を送りました。

I sent the letter according to my boss' instructions.

• 「〜に連{つ}れて」indicates "as something changes, another thing changes as well", which effects of change are simultaneous. This form is often used to express proportional relationship with events in respective clauses which the first clause triggers the second one.

例 (Example):

季節の変化につれて気温が変わる。

The temperature changes in accordance with seasons.

Hence, here is a simple comparison between all of them:

1) 「Aに伴{ともな}ってB」= A associated/accompanied with B

2) 「Aと共{とも}にB」= A (together) with B (along with A, B will happens)

3) 「Aに従{したが}ってB」= B according to A (A and B have parallel relationship)

4) 「Aに連{つ}れてB」= B happens as A happens (A and B are both occur simultaneously)

Additional references:

(English) As (change)

(Japanese) 「につれて、 に伴って、 に従って、 と共に」 の区別

(Japanese) ＜につれて＞、＜に従って＞、＜とともに＞、＜に伴って＞ の意味は同じですが、使い方は違います。どうやて分けたいいですか？