What it means
になる expresses a change into a new state, condition, role, or status. It follows a noun or a na-adjective with に, and it follows an i-adjective in its く form. It can also follow a plain clause with こと to express that something has been decided or will happen as a result of circumstances. The polite counterpart is になります.
Usage note
Do not confuse ことになる with ことにする. ことになる describes a decision or result that is made by circumstances, rules, or other people, while ことにする describes the speaker's own decision.
How to use it
彼は医者になります。
He will become a doctor.
この部屋は静かになります。
This room will become quiet.
夏は日が長くなります。
The days become longer in summer.
私は来月大阪で働くことになります。
It has been decided that I will work in Osaka next month.
彼は医者になる。
He will become a doctor.
この部屋は静かになる。
This room will become quiet.
夏は日が長くなる。
The days become longer in summer.
私は来月大阪で働くことになる。
It has been decided that I will work in Osaka next month.
Example sentences
来年の春から、この建物はホテルになります。
Starting next spring, this building will become a hotel.
来月から、姉は会社の新しい店長になることになりました。
It has been decided that my older sister will become the manager of the company's new store starting next month.
健康診断の結果、毎朝薬を飲むことになりました。
As a result of the health checkup, it has been decided that I will take medicine every morning.
この町