~ku wa ～くは

In Japanese, ~ku wa ～くは is the adverbial form of an i-adjective plus the wa は particle. This can work just like ~te wa ては, separating the adjective and an auxiliary into topic-focus, or just mark the adverb as topic.

• Grammar
• Contractions

Grammar

The wa は particle can mark an adverb as the topic. For example:

• chotto matte!
  ちょっと待って！
  Wait a bit!
  • chotto - adverb.
  • matte - verb in te-form.
• chotto wa matta
  ちょっとは待った
  A bit, [I] waited.

Since i-adjectives can be inflected into adverbs, it makes sense that they can be marked as the topic just like other adverbs.

• kawaiku naru
  可愛くなる
  To become cute.
  [You'll] become cute.
  • kawaiku - adverb.
  • naru - verb in non-past form.
• kawaiku wa naru kedo...
  可愛くはなるけど･･･
  Cute, [you'll] become, but...
  • You won't become something else. (see: contrastive wa は.)

Another case is that the wa は particle can separate base word and an auxiliary. For example:

• tabete-iru
  食べている
  To be eating.
  [He] is eating.
• tabete wa iru
  食べてはいる
  Eating, [he] is.

With i-adjectives the same thing happens.

Note, however, that with verbs, auxiliaries are attached to the te-form, but with the adjectives, they're attached to the adverbial form.

Furthermore, the only auxiliary that attaches to adjectives is the negative auxiliary nai ない. That means you'll only see this function as ~ku wa nai ～くはない. Observe:

• kirei da
  綺麗だ
  [It] is pretty
• kirei dewa nai kedo, kawaii
  綺麗ではないけど、可愛い
  Pretty, [it] isn't, but [it] is cute.
  • de - te-form of da.
• kawaii
  可愛い
  [It] is cute.
• kawaiku wa nai kedo, kirei da
  可愛くはないけど、綺麗だ
  Cute, [it] isn't, but [it] is pretty.

Contractions

A contraction of ~ku wa ～くは would be ~kya ～きゃ.

• kawaikya nai kedo..
  可愛きゃないけど･･･
  Cute, [it] ain't but...