Questions & Answers about Em đừng khóc; chị sẽ mua quà sinh nhật khác cho em.
They are Vietnamese personal pronouns based on family roles and relative age/status.
In this sentence:
- chị = an older female speaker, often like older sister / older young woman
- em = a younger person being addressed, often like younger sibling / younger person / younger friend
So the speaker is positioning herself as chị and talking to someone younger, em.
A very natural way to understand the relationship is:
- speaker: chị
- listener: em
This does not always mean they are literal sisters. Vietnamese often uses family-type pronouns socially.
Because it plays two different grammatical roles in the sentence.
Em đừng khóc
- em is the person being told not to cry
- in English, this is like you
chị sẽ mua quà sinh nhật khác cho em
- em comes after cho
- here it means the person who will receive the gift: for you
So both are the same person, but the function changes:
- first em = subject/addressee
- second em = indirect object / recipient