Simplify the following text for a Grade 9 native English-speaking person.
Original: Most Polish literature has been written in the Polish language , though other languages , used in Poland over the centuries , have also contributed to Polish literary traditions , including Yiddish , Lithuanian , Ukrainian , Belarusian , German and Esperanto . Until the early 18th century , a major language of Polish literature was Latin , widely popular across all of Western and Central Europe at the time .
Simplified: Polish literature was written in the Latin language during the Middle Ages ( there are only several Polish language texts from that times ) .