The Internet is noted for quizzes, and languages are no exception. One site that has quizzes in an assortment of languages is called Fun Trivia (that has quizzes on almost everything). The langauge quizzes can be found under the category world, and there are quizzes on over 50 languages.

A large number of French quizzes can be found on the About.com French language web site. The quisses range from beginner to advanced and cover a large number of subjects.  Here is a link to the test page:

http://french.about.com/od/tests/

The National French Contest (Le  Grand Concours) is a contest open to students grage 1 - 12. Information and sign up can be found at National French Contest

A web site that offers practice for the contest can be found at Le Grand Concours Practice Flashcards | Quizlet

A web site that offer 6 Italian tests, (beginner and intermediate level) can be found at https://www.fluentsimple.com/online-italian-test/.There are also other resources available on the web site. 

The Japanese Language Proficiency Test is a test that has been offered since 1984 in countries around the world. A web site that can provide more information on taking the test can be found at Taking the JLPT in the United States | American Association of Teachers of Japanese (aatj.org)

Although the National Latin Exam is mainly geared toward students, there are copies of previous exams on the web site and it is possible to practice Latin at what ever level you may choose by studying old exams. The previous exams can be found at https://www.nle.org/Exams/Information#previousexam

A web site that offers language lessons including quizzes on the lessons for a varieity of languages is MyLanguages.org. A list of the languages offered can be found at http://mylanguages.org/index.php

A web site from Language Trainers USA & Canada has practice questions in Portuguese and can be found at Portuguese Level Test | Test Your Portuguese Online | Language Trainers  Another web site where you can test your language abilities in Portuguese is Free Portuguese Language Quiz - Test Your Language

MasterRussian.com has a large number of tests and quizzes to help you learn. A list of their quizzes can be found at: http://masterrussian.com/index-8.shtml

Transparent Language web site offers proficiency tests in several languages including Spanish, French, Italian, Russian and Japanese as well as several other languages. This web site can be found at:

http://www.transparent.com/language-resources/tests.html

The National Spanish Exam is a proficiency test given by teachers to students in grades 6 - 12 to assess their Spanish language ability.  A web site providing practice exercises and vocabulary lists to prepare for this exam is provided by the AATSP (American Association of Teachers of Spanish and Portuguese).  The web site provides a large number of tests and vocabulary lists ranging from beginner to advanced and is completely free. The web site can be found at https://www.nationalspanishexam.org/index.php/exam-preparation/online-practice-exercises