התיק שלה על הכיסא.

In Hebrew, simple present-tense sentences often leave out the verb to be.
So התיק שלה על הכיסא literally looks like her bag on the chair, but it means Her bag is on the chair.

This is very normal in Hebrew.

Compare:

• התיק שלה על הכיסא = Her bag is on the chair
• התיק שלה היה על הכיסא = Her bag was on the chair
• התיק שלה יהיה על הכיסא = Her bag will be on the chair

In past and future, Hebrew uses forms of להיות (to be), but in the present, it usually does not.

Hebrew usually expresses this kind of possession as:

noun + של + pronoun

So:

• התיק שלה = literally the bag of hers
• natural English: her bag

This is different from English, where her comes before the noun.

Some common forms are:

• שלי = my/mine
• שלך = your/yours
• שלו = his
• שלה = her/hers
• שלנו = our/ours

So התיק שלה is the normal Hebrew way to say her bag.

It matches the owner, not the noun.

So in התיק שלה:

• תיק is a masculine noun
• שלה is feminine because the owner is female

If the bag belonged to a man, you would say:

• התיק שלו = his bag

So the form of של... tells you about whose it is, not about the grammatical gender of תיק.

The letter ה at the beginning of a noun is the Hebrew definite article, like English the.

So:

• תיק = a bag
• התיק = the bag

and

• כיסא = a chair
• הכיסא = the chair

In this sentence:

• התיק שלה = her bag / the bag that belongs to her
• על הכיסא = on the chair

A useful nuance:

• התיק שלה usually means her bag as a specific, definite bag
• תיק שלה can often mean a bag of hers

A simple pronunciation guide is:

ha-tik she-LA al ha-ki-SE

More naturally written in transliteration:

ha-tik shela al ha-kise

Stress usually falls like this:

• ha-TIK
• she-LA
• al
• ha-ki-SE

So the whole sentence sounds roughly like:

ha-TIK she-LA al ha-ki-SE

This is a very common Hebrew sentence pattern:

subject + location phrase

Here:

• התיק שלה = the subject/topic = her bag
• על הכיסא = the location = on the chair

So the sentence is basically:

Her bag + on the chair

with the present-tense is understood.

This kind of structure is extremely common in Hebrew:

• הספר על השולחן = The book is on the table
• הילד בבית = The boy is at home
• המפתחות בתיק = The keys are in the bag

Yes, you can, but it changes the emphasis.

• התיק שלה על הכיסא = neutral, normal order
• על הכיסא התיק שלה = more marked, like Her bag is on the chair with focus on the location, or On the chair is her bag

The original order is the most straightforward for a learner.
Putting the location first is possible, but it sounds more stylistic or contrastive depending on context.

Because there is no direct object here.

The word את is used before a definite direct object after a verb. But in this sentence:

• there is no expressed verb in the present tense
• הכיסא is part of a prepositional phrase: על הכיסא = on the chair

Since הכיסא is the object of the preposition על (on), not the direct object of a verb, את is not used.

Yes. Hebrew can also say:

התיק שלה נמצא על הכיסא

That means something like:

• Her bag is located on the chair
• Her bag is on the chair

But in everyday Hebrew, the shorter version without נמצא is very common and natural:

התיק שלה על הכיסא

So the original sentence is completely normal.