Examples have audio.

Demonstratives

Demonstrative Adjectives

There are two demonstrative adjectives in Persian: “این” for nearby things and “آن” for things that are further away. It does not matter whether what they precede is singular or plural.
این کوچه
آن ستاره
This alley
That star
این درختان
آن روزها
These trees
Those days

Demonstrative Pronouns

Demonstrative pronouns come in place of nouns in sentences. There are four demonstrative pronouns in Persian.
این
آن
این‌ها
آن‌ها
This
That
These
Those
These demonstrative pronouns should not be mistaken with demonstrative adjectives (این and آن) and the third person personal pronouns. Unlike demonstrative adjectives, number matters in demonstrative pronouns.
این را می‌دانم.
آن‌ها را دیروز خریدم.
I know this.
I bought those yesterday.

Definitive Demonstrative Adjectives

Definitive demonstrative adjectives are used to point at things while putting emphasis on them. In pronunciation, the stress goes on their first syllable.
با همین تفنگ کشتندش.
آن روز از همین راه رفتم.
همان روز همه‌چیز را فهمیدم.
این همان خیابانی است که گفتم.
امین هم همین را گفت.
They killed him with this same gun.
I took (lit. went from) the same path that day.
On the same day, I found out everything.
This is the street that I mentioned.
Amin said the same thing too.

Definitive Demonstrative Pronouns

The following pronouns, meaning “the same one(s)”, “exactly this/that one(s)” or “just this/that one(s)” are used a lot in Persian. In pronunciation, the stress goes on their first syllable if they are singular and on the last syllable (ها) if they are plural.
همین
همان
همین‌ها
همان‌ها
This
That
These
Those
Here are some examples:
از همین می‌ترسم.
همین کافی است.
همان‌ها پدرم را کشتند.
This is what I'm afraid of.
This is enough.
Those very people killed my father.