Ben kitabı çantama koyuyorum.

Yes, you can leave it out.

Turkish often drops subject pronouns because the verb ending already shows the subject. In koyuyorum, the ending -um tells you the subject is I.

So these are both natural:

• Ben kitabı çantama koyuyorum.
• Kitabı çantama koyuyorum.

Using ben adds emphasis, contrast, or a bit more clarity, like I’m the one putting the book in my bag.

Because it is the direct object of the verb, and here it is specific/definite, so it takes the accusative ending.

• base form: kitap = book
• accusative form: kitabı = the book / the specific book

There is also a sound change:

• kitap + -ı would give kitapı
• but Turkish often changes final p to b before a vowel
• so it becomes kitabı

This kind of change is very common in Turkish.

Not exactly in a one-to-one way, but very often that is the best translation.

Turkish does not have separate words like the and a/an in the same way English does. Instead, specificity is often shown by grammar.

So:

• kitap can mean a book or book
• kitabı usually means the book or a specific book

In this sentence, kitabı shows that the speaker is talking about a particular book, not just any book.

Çantama can be broken down like this:

• çanta = bag
• -m = my
• -a = to / into

So:

• çanta = bag
• çantam = my bag
• çantama = to/into my bag

Turkish often uses suffixes where English uses separate words.

Because çantama already includes my.

The -m inside çantama marks first-person possession, so my bag is already built into the word.

• çantama = into my bag
• benim çantama = into my bag, but with extra emphasis

Using benim is possible, but it is usually only added for emphasis, contrast, or clarity.

Turkish often expresses direction with the dative ending -a / -e instead of a separate preposition.

Here, çantama literally means something like to my bag, but with the verb koymak and the noun bag, English naturally translates it as into my bag.

So Turkish does not always match English word-for-word:

• çantama = to my bag / into my bag
• the exact English wording depends on context

Koyuyorum is the verb and means I am putting.

It comes from the dictionary form:

• koymak = to put

In this sentence, it is in the present continuous form:

• koyuyorum = I am putting

This tense is formed with -(I)yor plus a personal ending.

So very roughly:

• koy- = put
• -uyor = am/is/are ...-ing
• -um = I

Because the Turkish present continuous suffix is -(I)yor, not just -yor by itself in all cases.

With koymak, the stem is koy-. The vowel in the suffix changes by vowel harmony, so here it becomes -uyor:

• koy-
• koyuyor
• koyuyorum

So koyuyorum is the normal correct form.

Because Turkish is usually a subject–object–verb language.

So the basic order is often:

• Ben = subject
• kitabı = object
• çantama = direction/location complement
• koyuyorum = verb

Putting the verb at the end is very natural in Turkish.

Turkish word order is also fairly flexible, but moving things around usually changes the focus or emphasis, not the core meaning.

Yes, often you can, but the emphasis may change.

For example, these can all be possible in the right context:

• Ben kitabı çantama koyuyorum.
• Kitabı çantama koyuyorum.
• Kitabı ben çantama koyuyorum.
• Çantama kitabı koyuyorum.

The most neutral version is usually the one with the verb at the end and the other elements before it. Different orders can sound more marked or more emphatic.

The ending -a mainly shows direction toward something. The exact English preposition depends on the noun and the situation.

With bag, the natural English translation is usually into my bag.

So Turkish leaves some of that detail to context and to the meaning of the verb:

• çantama koyuyorum → I’m putting it into my bag

In another context, the same structure might be translated with to, onto, or something similar in English.