Additional nuance of より with time


It seems to me that より has virtually no meaning when used as shown below.

Consider these:

Please come before five O'clock:

  * 五時前に来てください

  * 五時 **より** 前に来てください

Please come after five O'clock:

  * 五時後に来てください (*ungrammatical as observed by sawa)

  * 五時 **より** 後に来てください

**(Question)** What does より add to the sentence? What additional nuance is
there? And why is omission of より acceptable for 五時前 but not 五時後?




`より` has an important role. It means "from", but in languages like English,
the word for "than" is morphologically distinct from the word "from". Don't
think of an extra `より` being added but think that `より` is omitted in the
examples without it. And in fact, `五時後` is ungrammatical.

As for why `五時前` is grammatical whereas `五時後` is not, I guess that it is
because it is much more frequent to ask someone to come a little bit before a
whole-hour time (to be ready for something) rather than a little bit after a
whole-hour time. Thence, it is likely that expressions in the form `五時前` had
more chance to make it into a fixed expression.




`より` has an important role. It means "from", but in languages like English,
the word for "than" is morphologically distinct from the word "from". Don't
think of an extra `より` being added but think that `より` is omitted in the
examples without it. And in fact, `五時後` is ungrammatical.

As for why `五時前` is grammatical whereas `五時後` is not, I guess that it is
because it is much more frequent to ask someone to come a little bit before a
whole-hour time (to be ready for something) rather than a little bit after a
whole-hour time. Thence, it is likely that expressions in the form `五時前` had
more chance to make it into a fixed expression.

