Arabic is spoken by more than 250 million people natively and another 250 people who are not native speakers. Arabic is used as a standard form of communication in the Middle East and Northern Africa, however, there are many different dialects used throughout the region.
Omniglot has a nice overview of the history of Arabic script as well as a list of characters and useful links for further study.
Speak 7 offers excellent lessons for those just starting to learn Arabic. The vocabulary is grouped by themes including animals, verbs, occupations, and weather.
Chinese is the native language of more than a billion people. Within the language classified as Chinese there are many sub-classifications. This is a rich and complex group of languages.
China Language is a comprehensive site with numerous English to Chinese dictionaries.
China Page has several resources, including an interactive flash card system.
Czech is the native language of around 12 million people. It is the primary language of the Czech Republic and is akin to Slovak and Polish.
Local Lingo has audio pronunciations with their lessons to make the learning experience easier.
French is spoken fluently by almost 130 million people. It is most common in France, but is also widely used in Canada.
About French has an extensive list of resources to help people who are interested in learning French.
The French Language Course has nine lessons that include family words, articles, genders, and sentence structure. Some of the lessons include audio pronunciations. German
German is the native language of more than 100 million people, and a second language to about 80 million. It is considered a West Germanic language, and it is the most prominent native language in the European Union.
About German has resources for students and teachers.
E Language School has lessons on German grammar, words, and phrases.
Hebrew is spoken fluently by about seven million people around the world. Hebrew and Arabic are the official languages of Israel.
Judaism 101 is an excellent place to begin learning basic Hebrew.
Omniglot provides Hebrew characters as well as a number of useful links to further resources.
Italian is spoken fluently by a little more than 60 million people. It is the most closely related to Latin of all the Romantic languages.
About Italian has resources for beginners, travelers, and for more advanced students.
Language School has a number of Italian courses including those that focus on phrases, grammar, and the basics.
Latin was spoken in ancient Rome, but is no longer the primary language of any nation. This language greatly influenced all of the modern romance languages.
Text Kit has a number of Latin textbooks and answer keys that can be downloaded.
Learning Languages offers two online Latin courses. Classical Latin teaches students the form of Latin most Roman books were written in, while Biblical Latin focuses on the form of Latin used most frequently in Bibles. Portuguese
Portuguese is spoken by nearly 200 million people worldwide. It is one of the most frequently used languages in the world.
Language School has a number of Portuguese lessons including those that cover basics, grammar, and specific phrases.
Easy Portuguese offers audio and written lessons on a number of topics.
Russian is the native language of almost 165 million people. The number of people speaking Russian as either a primary or secondary language is almost 280 million.
Master Russian has lessons for beginning through intermediary students.
Russian Lessons has basic vocabulary and grammar lessons as well as links to further resources.