Explanation
-(으)ㄹ게(요) states what the speaker will do as a promise or offer made to the listener, so it only takes I or we and only action verbs: -ㄹ게요 after a vowel (가다 → 갈게요), -을게요 after a consonant (먹다 → 먹을게요), -ㄹ게 without the 요 in 반말. -(으)ㄹ 거예요 is a plain plan or prediction; -(으)ㄹ게요 is a commitment shaped by the other person. 제가 전화할게요. — I'll call you.