なくなる

Phrase (Basic ㊦ 277)

It has reached the point where some state or action does not take place anymore.

Equivalent: Not ~ any more

易しい漢字も書けなくなった・なりました。: I cannot even write easy kanji any more.
前は酒をよく飲んでいたが、この頃は飲まなくなりました。: I used to drink sake a lot, but now I don't drink any more.
彼は前よく電話をかけて来ましたが、もうかけて来なくなりました。: He used to call me frequently, but he doesn't call me any more.
日本語はもう難しくなくなりました。: Japanese isn't difficult for me any more.
この郊外も地下鉄が来て不便ではなくなった。: This suburban area is no longer inconvenient because there is a subway now (literally: the subway has reached here).
やっと大学を出て学生ではなくなりました。: I finally graduated from college and am not a student any longer.

Formation

(i) Vinformal negative	なくなる	Where V is often a potential verb
	{話さ /話せ} なくなる	Someone doesn’t talk/can’t talk anymore
	{食べ /食べられ} なくなる	Someone doesn’t/can’t eat any more
(ii) Adjective い stem	くなくなる
	高くなくなる	Something isn’t expensive any more
(iii) {Adjective な stem/ Noun}	{では/じゃ} なくなる
	{静かでは/静かじゃ} なくなる	Something isn’t quiet any more
	{先生では/先生じゃ} なくなる	Someone isn’t a teacher any more

Notes

【Related Expressions】

Compare なくなる, Verb informal negative ようになる and もう~ない in the following sentences:

[1]

日本語が話せなくなった。
I cannot speak Japanese any more.

[2]

日本語が話せないようになった。
I've reached the point where I can't speak Japanese.

[3]

日本語がもう話せない。
I cannot speak Japanese any more.

[1] and [2] focus on both process and result, but [3] focuses only on result. Thus, [1] and [2] can take time expressions indicating the period of change, such as 一年のうちに 'within a year', 急に 'suddenly', とうとう 'finally', but [3] cannot. [1] is different from [2] in that the latter focuses on an indirect, circumstantial cause for the change, whereas the former focuses on a more direct one. Thus, [1] implies that the speaker cannot speak Japanese any more because he has simply forgotten Japanese but [2] implies that he cannot speak Japanese because the situation is such that there are no native speakers around to speak with.

(⇨ ようになる)