Jews have always learned to speak the languages of the countries they lived in. They have also spoken their own languages. The language of prayer has always been Hebrew. The language of conversation has varied from community to community, the 2 best known Jewish vernacular languages are Yiddish and Ladino.
Hebrew is one of the world's oldest languages. It is the language in which the Torah was originally written and in which it is still read in synagogues and houses of study. It was the language spoken by the biblical Hebrews. In orthodox communities the entire synagogue service is conducted in Hebrew. In progressive communities some of the service will be conducted in vernacular languages.
A few prayers are written in Aramaic rather than Hebrew. Aramaic was the dominant language spoken in the Near East from about the 4th Century BCE to the 6th Century CE. The two languages are quite closely related.
A modernised variant of Hebrew is spoken in Israel, although there are still ultra orthodox groups who find this distressing, taking the view that Hebrew should remain a languge purely for prayer until after the coming of Moshiach (the Messiah).
Written Hebrew uses an alphabet of 22 letters, 5 of which have different forms when they appear on the ends of words. The alphabet has only consonants, which makes it impossible for someone who is not familiar with the language to pronounce words from the written text. About 1200 years ago a system of dots and other marks was invented to act as vowels. These marks are technically known as diacritical marks. In Hebrew they are called nikkudim but they are often simply called points. A text which has the nikkudim is known as a pointed text.
Like other semitic languages (eg Arabic), Hebrew is written from right to left.
Here is a sample of pointed text. It is the account of the first day of creation from the opening of the Torah. The dots, dashes and little T shaped marks are the nikkudim; the other marks are cantillation notes (they tell the reader the tunes to sing).
There is also a cursive form of written Hebrew whose letters are very different in shape from their square capital equivalents.
Although the Hebrew alphabet is so different in appearance to the Latin alphabet which is used for English, they share the same origins. The first two Hebrew letters are ALEPH and BET (indeed we call it the Alephbet). You can find the whole Hebrew alphabet and a guide to its pronounciation by following this link to Judaism101. It will help to know that most Hebrew words are stressed on the final syllable.
There are quite a number of Hebrew loan words in English including amen, hallelujah, Satan, hosannah and sabbath. Many common names are also Hebrew in origin, eg. Benjamin, Jack, John, Michael, Rachel, Rebecca, Sarah to mention just a few.
Yiddish might be called a creole - a language originating in the mixture of two other languages. Yiddish has very strong Hebrew and German influences with a healthy admixture of other eastern European languages. There is great scholarly debate about how Yiddish developed but it was certainly spoken by Jews in the cities along the Rhine nearly 1000 years ago. By the beginning of the 20th Century Yiddish was the everyday language of Jewish communities across Germany, Poland, Lithuania and Russia. In the 1930s there were estimated to be about 10 million Yiddish speakers.
A significant number of the world's Yiddish speakers perished in the Holocaust. Many younger Jews in Europe, America and elsewhere abandoned Yiddish in favour of the languages of their home countries. As a result there are now serious concerns for the survival of Yiddish as a spoken language. In recent years, there have been hopeful signs of a revival, among younger Jews, of interest in speaking Yiddish.
English has many Yiddish loan words, eg mishmash, kybosh, bagel, schmaltz.
Yiddish is written in Hebrew characters but without nikkudim. Instead some of the characters do duty as vowels. Yiddish is often written in very tiny print and read with the help of a magnifying glass - perhaps a remnant of a time when paper was very expensive.
This is the language spoken by the Sephardic Jews of Spain in the 14-15th Centuries. It is, apparently, a dialect of Castilian Spanish with borrowings from Hebrew, Arabic, Turkish and Greek. (I know very little about Ladino - finding out more about it is on my ToDo list!).
