Grammar detail: 後（あと、のち、うしろ、ご）

あと and のち both refer to time. あと is by far the most common, and it is most commonly found in the construction or , or simply on its own:

Less commonly it is used with に or から, but they basically mean the same thing:

のち tends to be found in set phrases, such as the

てんきよほう

天気予報

standard,

は

晴

れのち

あめ

雨

(fine weather followed by rain). It is also found in the phrase

のち

後

に, but this is almost always written in kana:

It is also very commonly found in the form のちほど:

うしろ is used when referring to physical location - so it typically refers to a physical location of something behind something else:

All three terms あと, のち and うしろ can be written with the same kanji, 後, so the following guidelines may help you to distinguish the reading in different situations.

のち is almost always written in kana, so if there are no okurigana (as in for example 後に), あと is much more likely.

うし

後

ろ is usually followed by the okurigana ろ - but not 100% of the time, and this can sometimes be tricky. For example, consider the very similar set phrases うしろにつく (to place behind) and あとをついていく (to take the same route afterwards). Since both the あと and the うしろ may be written with kanji and no okurigana, you have to remember the rule that うしろ works with location and あと works with time. So, うしろにつく means to place physically behind, whereas あとをついていく means to take the same route afterwards (in time). Notice the slightly different verb forms used - つく means 'stick to', so conveys the sense of being physically close, and うしろ tells us where. ついていく adds the いく construction which can be used on its own to mean go towards or with, and あと adds the time element.

This brings us to the final piece of the puzzle: the use of 後 as a suffix to a noun. It means 'after' in time in just the same way as あと and のち, but it is read ご:

In this case, the kanji is almost always used, rather than kana, and there are no okurigana, so it can be hard to tell whether the reading should be あと or ご. Two guidelines will help: first, あと is usually followed by で, and if you see で, the reading is あと not ご. Second, although both ご and あと can be followed by に, ご is very commonly used with time or date expressions, for example:

The common set phrase その後 can be read as either そのご or そのあと. Some sources suggest そのご is more formal, but others suggest there is no distinction.