کیف من پشت صندلی است.

Word by word:

• کیف = bag
• من = I / me / my depending on context; here it means my
• پشت = back / behind
• صندلی = chair
• است = is

So the sentence literally comes out as something like:

• bag my behind chair is

Natural English: My bag is behind the chair.

In Persian, possessors usually come after the noun, not before it.

So:

• کیف من = my bag
• literally: bag of me

This is very normal in Persian. English says my bag, but Persian prefers bag my in surface word order.

Yes. In pronunciation, there is usually an ezafe sound, a short -e- link:

• کیفِ من
• pronounced roughly: keyf-e man

This linking sound connects a noun to something that describes or possesses it.

Important point:

• In normal Persian writing, that short vowel is usually not written
• So you see کیف من, but you often pronounce it keyf-e man

Yes, usually there is another ezafe link there too:

• پشتِ صندلی
• pronounced roughly: posht-e sandali

So the full sentence is commonly pronounced:

• keyf-e man posht-e sandali ast

Even though the written sentence does not show those short -e- vowels.

Literally, پشت means back or rear.

So:

• پشتِ صندلی = the back of the chair / behind the chair

In this sentence, the natural meaning is behind the chair.

Persian often uses nouns like this in location expressions, where English might use a simple preposition.

Persian does not have a regular definite article like English the.

So صندلی can mean:

• a chair
• the chair

The exact meaning depends on context.

If the meaning shown to the learner is the chair, that is completely normal. Persian often leaves definiteness unmarked.

The structure is:

• کیف من = subject
• پشت صندلی = location
• است = is

So the pattern is:

• My bag + behind the chair + is

In English, we say:

• My bag is behind the chair

In Persian, the verb است often comes at the end, which is very typical.

است is the formal written form of is.

It is the third-person singular form of to be.

So:

• او دانشجو است = He/She is a student
• کیف من پشت صندلی است = My bag is behind the chair

It finishes the sentence and tells you this is a statement about location.

In formal writing, yes, است is very common.

In everyday speech, people often use a shorter colloquial form:

• کیف من پشت صندلیه
• or even more naturally:
• کیفم پشت صندلیه

So:

• formal: است
• spoken: ـه / هست-type reduced forms depending on the sentence

For this sentence, صندلیه is the very natural spoken ending.

Yes, absolutely.

کیفم means my bag and is very common in everyday Persian.

It is made from:

• کیف = bag
• ـم = my

So these are both correct:

• کیف من پشت صندلی است
• کیفم پشت صندلی است

And in everyday speech, the most natural version is often:

• کیفم پشت صندلیه

A careful pronunciation is:

• keyf-e man posht-e sandali ast

A more natural spoken version is:

• keyfam posht-e sandaliye

A few pronunciation notes:

• کیف sounds like keyf
• پشت sounds like posht
• صندلی sounds like sandali
• است in careful speech is ast

Because Persian pronouns can serve more than one function depending on context.

• من by itself often means I
• after a noun, it can mean my

So:

• من آمدم = I came
• کیف من = my bag

This is very normal and something learners get used to quickly.

This sentence is grammatically correct and sounds neutral to formal, mostly because of است.

Levels of style:

• کیف من پشت صندلی است = correct, standard, a bit formal/written
• کیف من پشت صندلیه = more conversational
• کیفم پشت صندلیه = very natural everyday speech

So the version you were given is excellent for learning standard Persian grammar.