Thank you Susan, Ruthi, and Michael. You are all very helpful.

 I will try them one by one.  :)

Hi Min,

I teach English online and I mostly use games like the ones on coolenglish.com. Of course it depends on the level and age of the students, and of course online teaching is different from face to face. There are many websites that I use to teach online like matching games or crossword puzzles, hangman and so on. If you google you will find thousands of them.

I also just remembered a REALLY fun word game that I have played at parties.  It could be adapted for large groups and there is a junior version.  It´s called Blurt.  It is a word race game. https://www.amazon.com/Educational-Insights-2917-EDUCATIONAL-INSIGHTS/dp/B001QOGXPK

The same company has some other games I have not played but look like they would be good for language leaners:

Super Sleuth https://www.amazon.com/dp/B00ATWSQQE/ref=pd_lpo_sbs_dp_ss_1?pf_rd_p=1944687642&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=B001QOGXPK&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=54YSGXJF9SMB1GKQ9MDZ

Wordical https://www.amazon.com/Educational-Insights-2865-Wordical/dp/B00ATWSRGI/ref=pd_bxgy_21_img_2?ie=UTF8&psc=1&refRID=6QE39QMYNDYE977705PW

Many word games could be used to teach languages.  I would expect Scrabble to be especially good to build vocabulary.  

You can also make your own classroom versions of a quiz bowl, dividing classes up into groups where the groups compete for answering questions. I do not think quiz bowls are common except in English-speaking countries.  Here is a link https://en.wikipedia.org/wiki/Quiz_bowl

I think Wheel of Fortune could also be used to increase vocabulary and teach idioms. Here is a link to the online game. http://www.gsn.com/games/free/wheel/  It does not seem to have easy to find instructions, but you could probably find some examples on YouTube if you have never seen this game show. 

Probably any of the word games on the Game Show network could be used to increase vocabulary. http://www.gsn.com/word-games/ Some of these games you can find as board games that could be used in class as well.  

I am currently taking a TEFL course and they use some of the videos from www.teflvideos.com   There are some videos there on using games in a TEFL classroom. Apparently a lot of teachers use ideas from common games and make their own.

I was thinking today that the site https://roll20.net/ ;, that can be adapted to make any type of game, such as a board game, playable by people online as a group, would have very interesting uses to make your own games and teach classes online with game activities. Roll20.net is popular primarily among role-playing game players, but the system is designed to be adaptable for any games.