Ấy (De. Pro.)

Situations

S1: Lan, pointing at a young lady standing at the door, asked Nam: "Who is that?", Nam answered:

Ấy là cô thư ký mới.
(That is the new secretary.)

Ấy here is a pronoun indicating a person at a distance from both speaker and listener.

S2: Hung's mother punished him because he was lazy in schoolwork. After punishment, she said:

Ấy là mẹ muốn con chăm chỉ hơn.
(That is because I want you to be more studious.)

The pronoun ấy refers to the mother's punishment.

Definition

Ấy, as a demonstrative pronoun, is used to refer to a person or thing far from both speaker and listener, or to refer to something which has just been mentioned.

As a subject, the pronoun ấy occurs only at the beginning of the sentence and goes only with the copula là. Note that ấy cannot be used as an object.

In fact, ấy is not often used as a subject, but đó / đấy are used instead to indicate a person or thing which is far from the speaker and the listener, or which has just been mentioned.

[1] — Ấy / Đó / Đấy là tôi muốn giúp anh.
(It is that I want to help you.)

Đó / đấy can occur as a complement of place, but ấy cannot.

[2] — Tôi đã sống ở đấy / đó / *ấy 10 năm.
(I had been living there for 10 years.)

Note: Đó is often used in the Southern dialect.

The pronouns đây, này refer to a person or thing close to both the speaker and the listener. Cf:

[3a] — Ấy là em gái tôi.
(That is my younger sister.)

[3b] — Đây là em gái tôi.
(This is my younger sister.)

[3c] — Này là chị ruột, này là em dâu.
(This is my blood elder sister, and this is my sister-in-law.)

Note: The pronoun này is rarely used as a subject of the sentence.