I just came across this sentence while studying verb する

山田さんは英語の先生をしている - (As per the book it translated to " Yamada-san is an English
Teacher)

  * My question is why did not we use です instead of する and make the sentence into 山田さんは英語の先生です (which also has the same meaning)? 
  * Further, is there any difference in the nuance between the two sentences?
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2020-05-03T11:37:30.057
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2020-05-09T20:49:53.980
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question
grammar word-choice verbs
Difference between です and をする in the following passage
It's close to "Yamada-san works as an English teacher".
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2020-05-03T17:14:11.457
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です is a statement that **A is B** , while している is a denotation of being so.

  * 山田さんは英語の先生をしている -- has been an English teacher. 
  * 山田さんは英語の先生です -- is an English teacher. 

On the first one, we surely understand she is doing now. The latter one is a
general phrase and also might 山田さん retired some time ago, but she is still a
teacher. In case of this, `先生をしていた` would fit perfectly.
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2020-05-08T03:15:44.200
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2020-05-09T20:49:53.980
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Here, we are comparing two options:

> a) 山田さんは英語の **先生をしている。** / しています。
>
> b) 山田さんは英語の **先生だ。** / です。

Let's focus on (a) first. If you check this
[link](https://dictionary.goo.ne.jp/word/%E7%82%BA%E3%82%8B/), you'd see that
it says:

> **2** ㋑ある役割を努める。

This roughly translates to "to play a role." In other words, you can translate
(a) as "Yamada-san plays the role of a teacher." He may or may not be
professional/licensed teacher in the strictest sense of the word, but he acts
as a teacher.

Now, let's look at (b). From this
[link](https://dictionary.goo.ne.jp/word/%E3%81%A7%E3%81%99/#jn-151501), です
has this definition

> 断定の意を表す。

This translates "to express a conclusion or decision." We see that だ or です is
used in presenting that something--a concrete or abstract fact-- _ **is**_.
This is actually a conclusive statement (as opposed to expressions such as
でしょう・だろう or かもしれません・かもしれない) and therefore shows certainty. In other words,
this is the most direct translation of "Yamada-san is an English teacher."

Now, why did the book's authors choose the translation "Yamada-san is an
English teacher." for "山田さんは英語の先生をしている." I think this is because "Yamada-san
is an English teacher." sounds more direct and natural than "Yamada-san plays
the role of a teacher."
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2020-05-09T06:55:50.947
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2020-05-09T13:37:49.353
2020-06-17T08:18:27.500
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