Although a dictionary can provide you with this information, it's easier to look for a premade list that caters to players of these games when broadening your vocabulary.
Four letter words are commonly used when playing these games as they're readily used in the English language. While these common words may not produce the highest scores, they're great for getting rid of difficult or excessive letters in your rack.
They - They is a common multipurpose pronoun used to talk about many people or objects.
From - People typically like to talk about where they originally come from.
That - From this to that, this word is so popular you may hear it so frequently that you don't even notice.
With - When you're with someone else or completing a project with a certain tool, it would be hard to say it without this word.
Some - When you don't want all or none of something, the word some comes in handy.
What - What would you do without the word what?
Were - This past tense verb is a great way to find out what they were doing or where they were going.
Word - Considering you're likely looking for a word to play for a word game, it's only natural to think of this word.
Said - Words can't be unspoken once they've been said.
Good - It's always good to have a word where you can use up some extra vowels.
Free Dictionary claims that there are 149,165 words that are made using four letters. However, the Official Scrabble Player's Dictionary states that there are 3,996 legal words that can be used in that specific word game.
The highest-scoring words with Q that you should always have in mind are: QUIZ, QOPH, QUAY, QUEY. All of these words are playable in both Scrabble and WWF.
Common words that you can make beginning with the letter Z are ZARF, ZONE, ZEIN, ZEST, and ZILL. If you're looking for the higher-scoring ones, playable in both Scrabble and WWF, it's worth memorizing ZIZZ, ZYME, ZEKS, ZERK.