This question already has an answer here:

寝る → 寝るようになる

  1. 寝ないようになる
  2. 寝なくようになる
  3. 寝なくなる

Hi guys, sorry if this has been asked before. I've learned in class that 寝なくなる is the valid form, but are the first two forms valid as well?

marked as duplicate by Eiríkr Útlendi, Blavius, Earthliŋ Feb 7 '16 at 8:39

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

  • 8
    Related: japanese.stackexchange.com/q/16328/1478 – snailboat Dec 13 '15 at 5:48
  • 2
    Except that #2 is ungrammatical (spoiler), the question seems duplicate with the post above. Close or not? – broccoli forest Feb 6 '16 at 14:47
  • @John I closed this question, because it seems to be answered by the linked question (together with broccoli forest's comment). If you want to understand why 寝なくようになる is ungrammatical, you can edit this question (or ask a new question). In case you edit the question, it will be automatically queued for reopening. – Earthliŋ Feb 7 '16 at 8:43