Polish indeed has no words for “the” or “a.” You rely on context.
Approximate phonetic guide:
• On [ɔn]
• czyta [ˈt͡ʂɨ.ta] (“CHIH-tah,” stress on the first syllable)
• książkę [ˈkɕɔ̃ʂ.kɛ] (“KYAWN-sh-keh,” stress on the first syllable)
• cały [ˈt͡sa.wɨ] (“TSA-wih,” stress on “tsa”)
• czas [t͡ʂas] (“chas”)
Polish stress almost always falls on the penultimate syllable of each word.
Absolutely. Word order is flexible in Polish. For example:
• On cały czas czyta książkę. (emphasis on cały czas)
• Cały czas on czyta książkę. (even stronger emphasis on duration)
• On czyta cały czas książkę. (less common, but possible)
All convey roughly the same meaning; placement shifts the focus.