Czy możesz polecić mi dobrą książkę po polsku?

Czy is a question particle. It helps turn a statement into a yes/no question.

• Możesz polecić mi dobrą książkę po polsku. = You can recommend me a good book in Polish. / You can recommend a good book to me in Polish.
• Czy możesz polecić mi dobrą książkę po polsku? = Can you recommend me a good book in Polish?

In everyday speech, Polish speakers often drop czy and just use intonation:

• Możesz polecić mi dobrą książkę po polsku?

That is still completely natural.

Możesz is the 2nd person singular form of móc = to be able to / can.

So:

• mogę = I can
• możesz = you can
• może = he/she/it can
• możemy = we can
• możecie = you all can
• mogą = they can

In this sentence, Czy możesz... ? means Can you... ?

This is about aspect, which is very important in Polish verbs.

• polecić = perfective
• polecać = imperfective

Here, polecić is used because the speaker is asking for one complete recommendation: Can you recommend... ?

Compare:

• Czy możesz polecić mi dobrą książkę? = Can you recommend a good book to me?
• Możesz mi polecać książki. = You can recommend books to me / keep recommending books to me.

In requests like this, the perfective form is very common because it refers to a single completed action.

Both mi and mnie can mean to me, but mi is the usual unstressed dative form and is much more natural here.

• polecić mi książkę = recommend a book to me

Use mnie when you want emphasis, contrast, or after certain prepositions:

• Mnie możesz polecić coś trudniejszego, a jemu coś łatwiejszego. = You can recommend something harder to me, and something easier to him.

So in your sentence, mi is the normal choice.

Because polecić takes a direct object, and in Polish the direct object often goes into the accusative case.

The base form is:

• dobra książka = a good book

But as the object of the verb, it becomes:

• dobrą książkę

Both the adjective and the noun change to match:

• dobra → dobrą
• książka → książkę

This is a very common pattern with feminine nouns ending in -a.

Because książka is a feminine singular noun, and feminine nouns ending in -a usually change like this in the accusative:

• nominative: książka
• accusative: książkę

The adjective changes too:

• nominative: dobra książka
• accusative: dobrą książkę

This happens because the book is the thing being recommended.

Po polsku means in Polish.

This is a fixed and very common pattern in Polish:

• po angielsku = in English
• po polsku = in Polish
• po niemiecku = in German
• po hiszpańsku = in Spanish

It uses po + an adverb-like form derived from the language name.

So:

• książka po polsku = a book in Polish
• mówić po polsku = to speak Polish

In this sentence, it most naturally describes the book:

• dobrą książkę po polsku = a good book in Polish

So the idea is a good Polish-language book, not recommend in Polish.

If you wanted to emphasize that someone should give the recommendation in Polish, you would usually phrase it differently.

Yes, Polish word order is fairly flexible, although some versions sound more neutral than others.

The most neutral version is:

• Czy możesz polecić mi dobrą książkę po polsku?

Other possible orders:

• Czy możesz mi polecić dobrą książkę po polsku?
• Możesz polecić mi dobrą książkę po polsku?
• Czy dobrą książkę po polsku możesz mi polecić? — possible, but marked/emphatic

A very common alternative is:

• Czy możesz mi polecić dobrą książkę po polsku?

Both are natural.

Polish has no articles, so there is no direct equivalent of a or the.

• dobrą książkę can mean a good book or the good book, depending on context.

In this sentence, English naturally uses a good book, but Polish does not need any article.

Yes, but the meaning may be slightly different.

• książkę po polsku = a book in the Polish language
• polską książkę = a Polish book, which may suggest a book by a Polish author, from Poland, or culturally Polish

Sometimes they overlap, but not always.

For example:

• A translation of an English novel into Polish is książka po polsku, but not necessarily polska książka.

So po polsku is the safer choice when you mean the language.

It is polite and natural, but still fairly direct and informal because it uses możesz, which is the singular you form.

You would use it with:

• a friend
• a classmate
• someone your age in an informal situation

If you want to be more formal, use może Pan / może Pani:

• Czy może Pan polecić mi dobrą książkę po polsku?
• Czy może Pani polecić mi dobrą książkę po polsku?

That is appropriate when speaking to a stranger, teacher, shop assistant, or someone you want to address respectfully.

It can look intimidating, but here is a rough guide:

• książkę ≈ kshyonsh-keh

A few helpful points:

• ksi often sounds roughly like ksh
  • a soft sound
• ąż contains a nasal vowel
• ż sounds like the s in measure
• ę at the end is often pronounced less strongly than learners expect, and before k it can sound closer to en/em depending on speech

You do not need perfect pronunciation right away. The important thing is to recognize that książkę is the accusative form of książka.