When on earth do you use ごろ (goro)?


I was in class the other day and my せんせい was teaching us about using ぐらい
(gurai) as in ...どの ぐらい かかりますか (how long will it take), and mentioned another
form of ぐらい being ごろ (goro), and never elaborated on how or when to use it.
Can anyone explain it to me?




In English, ～ぐらい and ～ごろ mean _about, around, approximately_.

  1. ～ぐらい is used for approximate quantities, which include duration.

    1. このXはいくら **ぐらい** ですか。 _ **About** how much is this X?_  
そのXは５００円 **ぐらい** です。 _That X is **about** 500 yen_.

    2. 六時間 **ぐらい** 図書館にいました。 _I was at the library for **about** 6 hours._
  2. ～ごろ is used for approximate points in time, with an optional に.

    1. 八時 **ごろ** （に）公園に来ました。 _I came to the park **around** 8._
    2. 六時 **ごろ** 帰ります。 _I will return **around** 6._

You cannot use ～ごろ in 1. Some people use ～ぐらいに in 2, but I do not know enough
to comment further on that usage.

By the way, I think 「どのぐらいかかりますか」 is more accurately " **About** how long will
it take?"

