What are the guidelines for omitting particles?


I've recently discovered that certain particles could be omitted from a
Japanese sentence (to help make it shorter), and still preserve the original
meaning. Unfortunately, most resources about this topic that I've looked at
are vague at best; and some even contradict each other!

This question is really a few sub questions (but I really don't think each one
deserves its own thread since they're so closely related.) The answers don't
have to be too detailed; just general points are fine. Anyways, the things I'd
like to know are:

  * Which particles can be omitted from sentences?
  * Does the omission of particles make a sentence informal/impolite?
  * When can particles be dropped? (e.g. How can you decide that it's okay both socially and grammatically)
  * Can multiple particles be dropped in a single sentence?




> Which particles can be omitted from sentences?

は, が, and を are often dropped; に sometimes. か, as a sentence-final question
particle, can be replaced with intonation.

> Does the omission of particles make a sentence informal/impolite?

Informal yes, but not necessarily impolite. Dropping particles is only for
spoken Japanese, so you won't see it in (proper) writing.

> When can particles be dropped? (e.g. How can you decide that it's okay)

When the situation allows. Speaking informally to someone above you or with
whom you don't have a close relationship is impolite. But if the situation
lets you speak informally, you can.

In situations where polite Japanese is called for (speaking to your
boss/teacher/doctor/etc or giving a formal speech/presentation), all particles
must be kept in the sentence. Omitting particles does not change the meaning
of the sentence or make it incorrect per se, since the missing particles can
be inferred from context and word order, but it does make the sentence
informal and thus unsuitable for polite contexts.

As noted above, in writing (excluding Twitter, blogs, and other informal
variants of writing) all particles must be kept.

If you are unsure as to whether to keep or omit particles, a good rule of
thumb is to err on the side of keeping the particles.

> Can multiple particles be dropped in a single sentence?

Yes.

Examples:

> これあげるよ。（＝これ **を** あげるよ。） You can have this. (lit. "I'll give this [to
> you].")
>
> おまえ昨日、学校行った？（＝おまえ **は** 昨日、学校 **に** 行った **か** 。） Did you go to school
> yesterday? ( _slightly masculine_ )
>
> あたしスイカ好き。（＝あたし **は** スイカ **が** 好き。） I like watermelon. ( _feminine_ )

が and を, as you recall, are dropped when the part of the sentence they mark is
made into the scope/topic (marked by は):

> 図書館でこの本を借りました。 I borrowed this book at the library.
>
> この本をは図書館で借りました。 (making この本を the scope)
>
> この本は図書館で借りました。 (replaced ungrammatical をは with は)




> Which particles can be omitted from sentences?

は, が, and を are often dropped; に sometimes. か, as a sentence-final question
particle, can be replaced with intonation.

> Does the omission of particles make a sentence informal/impolite?

Informal yes, but not necessarily impolite. Dropping particles is only for
spoken Japanese, so you won't see it in (proper) writing.

> When can particles be dropped? (e.g. How can you decide that it's okay)

When the situation allows. Speaking informally to someone above you or with
whom you don't have a close relationship is impolite. But if the situation
lets you speak informally, you can.

In situations where polite Japanese is called for (speaking to your
boss/teacher/doctor/etc or giving a formal speech/presentation), all particles
must be kept in the sentence. Omitting particles does not change the meaning
of the sentence or make it incorrect per se, since the missing particles can
be inferred from context and word order, but it does make the sentence
informal and thus unsuitable for polite contexts.

As noted above, in writing (excluding Twitter, blogs, and other informal
variants of writing) all particles must be kept.

If you are unsure as to whether to keep or omit particles, a good rule of
thumb is to err on the side of keeping the particles.

> Can multiple particles be dropped in a single sentence?

Yes.

Examples:

> これあげるよ。（＝これ **を** あげるよ。） You can have this. (lit. "I'll give this [to
> you].")
>
> おまえ昨日、学校行った？（＝おまえ **は** 昨日、学校 **に** 行った **か** 。） Did you go to school
> yesterday? ( _slightly masculine_ )
>
> あたしスイカ好き。（＝あたし **は** スイカ **が** 好き。） I like watermelon. ( _feminine_ )

が and を, as you recall, are dropped when the part of the sentence they mark is
made into the scope/topic (marked by は):

> 図書館でこの本を借りました。 I borrowed this book at the library.
>
> この本をは図書館で借りました。 (making この本を the scope)
>
> この本は図書館で借りました。 (replaced ungrammatical をは with は)

