Explanation
Decide to do something, make a decision.
Formation
Verb-る + ことにする
Detailed explanation
The ～ることにする grammar point is used to express that someone has made a decision to do something or has decided on a specific course of action. It is formed by attaching ことにする to the verb in its る form.
Examples
来週、ジムに行くことにしました。
Raishuu, jimu ni iku koto ni shimashita.
I decided to go to the gym next week.
この靴を買うことにしました。
Kono kutsu wo kau koto ni shimashita.
I decided to buy these shoes.
毎日、散歩をすることにしました。
Mainichi, sanpo wo suru koto ni shimashita.
I decided to take a walk every day.
彼に電話をかけることにします。
Kare ni denwa wo kakeru koto ni shimasu.
I’ve decided to call him.
Practice
Grammar content sourced from hanabira.org.