You can use it when you want to use direct speech or indirect/reported speech.
- 이라고 goes for words ending in a consonant while 라고 goes for words ending in a vowel.
- In indirect speech, (이)라고 is usually used with words related to speaking (말하다, 이야기하다, 대답하다), but also with 하다 (in this case it means “to say/tell/talk”).
Examples:
1.Direct speech
- 이거라고! / This is it!
- 자동차라고. / It’s a car.
2.Indirect/reported speech
- 이 사람이 학생이라고 말해요. / (He/She/They) say(s) this person is a student.
- 이 사람이 ‘학생’이라고 말했어요. / This person said ‘student’.
Vocabulary:
- 말하다 = to speak
- 이야기하다 = to have a conversation
- 대답하다 = to answer
- 하다 = to do
- 이거 = this, this thing
- 자동차 = car
- 사람 = person
- 학생 = student
Read more here.