If you are looking for a great way to use 4 letter words during your game in scrabble then we really recommend you check out this site. They have a ton of great resources on 4 letter words specifically, but you can find plenty on many other subjects as well.
Lets recap what they say
Pertaining to 4 letter words specifically there are 6 main groups you want to pay special attention to and here they are...
Did you know there are over 5,000 4 letter words you can play in scrabble? (5454 to be exact). This is a much better option for you and gives you a better chance of finding words easier than the other 2 letters words (124 total) and 3 letter words (1292 total). In fact there are twice as many 4 letter words in scrabble than 3 letter words.
Many of these words are also going to contain vowels which is why paying attention to vowel heavy 4 letter words is going to give you your greatest chance, as long as you have a balanced rack of course.
If you stick to these rules you will be golden!