این کیف از چمدان من سبک تر است، اما آن یکی خیلی سنگین است.

Here از means than, not from.

In Persian comparisons, the pattern is:

X از Y adjective‌تر است
= X is more adjective than Y

So:

این کیف از چمدان من سبک‌تر است
means This bag is lighter than my suitcase.

Even though از often means from in other contexts, after a comparative adjective it usually means than.

Persian usually forms the comparative by adding تر to an adjective.

So:

• سبک = light
• سبک‌تر = lighter

This is very similar to adding -er in English.

More examples:

• بزرگ = big

• بزرگ‌تر = bigger

• کوچک = small
• کوچک‌تر = smaller

In your sentence, سبک‌تر is the comparative form meaning lighter.

The most standard modern spelling is سبک‌تر, with a half-space between the adjective and تر.

So this is usually preferred:

• سبک‌تر

But many learners will also see:

• سبک تر

That version is common in casual typing or when people do not use the half-space correctly.

So:

• سبک‌تر = more standard
• سبک تر = common but less precise typographically

Both represent the same word and meaning.

The first clause is:

این کیف از چمدان من سبک‌تر است

A helpful breakdown is:

• این کیف = this bag
• از چمدان من = than my suitcase
• سبک‌تر = lighter
• است = is

So Persian keeps the verb است at the end, which is normal.

A rough literal order is:

This bag than my suitcase lighter is.

That sounds odd in English, but it is normal Persian structure.

Yes. In pronunciation, Persian usually has an ezafe sound between the noun and the possessor:

• چمدانِ من
• pronounced roughly chamedân-e man

This means my suitcase.

In normal Persian writing, that ezafe vowel is often not written, especially before words like من.

So you see:

• چمدان من

but you pronounce it like:

• چمدانِ من

This is very common in Persian.

آن یکی means that one.

Breaking it down:

• آن = that
• یکی = one

Together, they mean that one or sometimes the other one, depending on context.

In this sentence, it avoids repeating کیف:

• اما آن یکی خیلی سنگین است
• but that one is very heavy

So instead of saying اما آن کیف خیلی سنگین است, Persian uses آن یکی to mean that one.

Because the second clause is not making another comparison. It is just describing that item directly.

• سنگین است = it is heavy
• خیلی سنگین است = it is very heavy

If the sentence said سنگین‌تر است, that would mean heavier, and then you would expect a comparison such as heavier than...

So in this sentence:

• first clause = a comparison: lighter than my suitcase
• second clause = a simple description: very heavy

است means is, and Persian normally puts the verb at the end of the clause.

So:

• سبک‌تر است = is lighter
• سنگین است = is heavy

In formal written Persian, است is often included.

In everyday speech, it is often shortened:

• سبک‌تره
• سنگینه

And sometimes in very casual speech, the copula can be omitted if the meaning is obvious, but learners should first get used to the full form.

So the sentence as written is normal and fairly formal/written in style.

خیلی means very.

It comes before the adjective it modifies:

• خیلی سنگین = very heavy
• خیلی خوب = very good
• خیلی بزرگ = very big

So:

آن یکی خیلی سنگین است
= That one is very heavy

Its placement is straightforward: خیلی usually comes right before the adjective.

These are demonstratives:

• این = this
• آن = that

So:

• این کیف = this bag
• آن یکی = that one

The basic idea is similar to English:

• این is for something near the speaker or mentally close
• آن is for something farther away or less immediate

In everyday spoken Persian, آن often becomes اون in pronunciation and informal writing.

A natural colloquial version would often be:

این کیف از چمدون من سبک‌تره، اما اون یکی خیلی سنگینه.

Some common spoken changes are:

• چمدان → چمدون
• آن → اون
• است → -ه

So the written sentence is correct and standard, but the spoken version is often a little different.

A simple learner-friendly pronunciation would be:

in kif az chamedân-e man sabok-tar ast, ammâ ân yeki kheyli سنگین ast

More naturally, with the Persian sounds:

in kif az chamedân-e man sabok-tar ast, ammâ ân yeki kheyli sangin ast

If you want a more colloquial pronunciation, it would sound closer to:

in kif az chamedun-e man sabok-tare, ammâ un yeki kheyli sangine

The main things to notice are:

• چمدان من is pronounced chamedân-e man
• سبک‌تر has the comparative -tar
• آن یکی is that one
• خیلی is pronounced kheyli