38906
一週間後に行く means : We arrive there in a week.  
日本語は九ヶ月間勉強している means : I've been studying Japanese for 9 months.  
ニ日間に休む means : absent for 2 days.
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2016-09-02T02:04:30.217
38897
2016-09-08T18:51:56.773
2016-09-02T03:07:06.417
15891
15891
question
grammar meaning
Is this grammar correct? (span of time)
~~一週間後に行く means "we'll go there after a week".

"We arrive there in a week" should be 一週間の内{うち}に / 一週間以内に / 一週間で 着く.~~

"I've been studying Japanese for 9 months" for 日本語は九ヶ月間勉強している is correct.

ニ日間に休む means "I'll take a break sometime within a certain two days".

"Absent for 2 days" should be 二日間 いない / 休む
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2016-09-02T13:12:12.397
38906
2016-09-08T12:13:36.580
2016-09-08T12:13:36.580
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> 日本語は九ヶ月間勉強している means : I've been studying Japanese for 9 months.

it's good, but (probably) a more usual way is: 私は日本語を ......

> ニ日間に休む means : absent for 2 days.

Remove NI. -- it's very tempting to put a NI there ... even native Jp people
do it (exactly that) incorrectly many time over in Web pages.

2 examples of misplaced (incorrectly inserted NI) at: [Misplaced(?) に in
たった4週間の間に毎日3Lの水を飲み続けた女性の変化がヤバすぎ！](https://japanese.stackexchange.com/questions/38590/misplaced-%e3%81%ab-
in-%e3%81%9f%e3%81%a3%e3%81%9f4%e9%80%b1%e9%96%93%e3%81%ae%e9%96%93%e3%81%ab%e6%af%8e%e6%97%a53l%e3%81%ae%e6%b0%b4%e3%82%92%e9%a3%b2%e3%81%bf%e7%b6%9a%e3%81%91%e3%81%9f%e5%a5%b3%e6%80%a7%e3%81%ae%e5%a4%89%e5%8c%96%e3%81%8c%e3%83%a4%e3%83%90%e3%81%99%e3%81%8e)

* * *

What you can do instead of inserting a NI :

  * ニ日間 休む -- (with hankaku-space) -- I do this, but it's not accepted practice.

  * ニ日間、休む -- It's ok if you don't overdo it (put too many commas, or 、 TEN ).

Some variations are: (TEN (、) is optional in each example)

  * ニ日間は、休む -- one meaning is [ at least that amount ]

  * ニ日間も、休む -- one meaning is [ that amount is too much ] 

  * ニ日間しか、休まない -- the meaning is [ that amount/period is short ]
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2016-09-02T19:11:31.623
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2016-09-08T18:51:56.773
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