くなる・
Use this construction when a person, thing, quality, or condition changes into a new state. It focuses on what becomes different, without presenting someone as deliberately making the change.
Name the resulting state
The adjective or noun before なる names the new state, not the original one. Tense and politeness appear on なる: for example, なった is past, while なります is polite.
Changes in quality, condition, and identity
The change need not happen by itself
This construction does not mean that a change must be spontaneous or gradual. An outside event may cause it; the sentence simply follows the person or thing that changes and reports the resulting state.
Becoming different versus making something different
With なる, the screen is presented as the thing that changes, so it is marked by が. With する, the sentence presents an action that makes the screen different, so the screen is marked by を.
When an action stops happening
毎朝コーヒーを飲んでいましたが、今は飲まなくなりました。
I used to drink coffee every morning, but now I no longer do.
AnalyzeThe first clause makes it clear that the action happened before and then ceased.
More examples
秋になって、朝は涼しくなりました。
Autumn arrived, and the mornings became cooler.
Analyze娘は来月、五歳になります。
My daughter will turn five next month.
Analyze駅の近くは前より便利になりました。
The area near the station has become more convenient than before.
Analyze雨がやんで、空が明るくなりました。
The rain stopped, and the sky became brighter.
Analyzeこの店は夜になると忙しくなります。
This restaurant gets busy when night comes.
Analyze最近、テレビをあまり見なくなりました。
Recently, I have stopped watching much television.
Analyze