AV + (ㄹ/을)게요
This is a slightly complicated ending.
This ending is a future form ending similar to (ㄹ/을)거예요 except in this case, we are making a decision based on an event, such as what someone else said, or a change of plans, or a promise to do something.
To make this ending, we conjugate the verb with ㄹ if the ending is a vowel and 을 if the ending is a consonant and add 게요 to the end.
With verbs ending in ㄹ already, we don’t need to add ㄹ/을.
1. This ending is used when we are promising another person we will do something, or resolving to do something.
2. This ending is used when we are changing our plans or decide to do something as a result of what someone else said or another event, or looking for a reaction from someone.
3. The 반말 ending is (ㄹ/을)게.
저도 갈게요. – Well in that case, I’ll go too.
공부할게요. – I promise to study.