Don’t praise but encourage your students.
Many students strive to be 100 % correct. But remind them learning is about making mistakes and learning from them. I still get students, after an exercise, admit to me rather sheepishly that they got 2 wrong, and the feel guilty about admitting that. I tell them over and over that that is OK and that making mistakes is a good thing. But many of my students are often from difficult backgrounds and simply want strokes which, you know, is also understandable.
So what should you say to them when they do well? Many adjectives come to mind which seem like praise but maybe, if they say “Teacher, I got 2 wrong” then you say with a big smile, “That means you got 8 correct. That’s fabulous”. Or, you can take a different tack and answer: “Which ones did you get wrong and why do you think you got those ones wrong?”.
However, you really must weigh up your objective as a trainer or teacher. What do you want from your students? Do you want them to be 100% correct at every turn? Or do you want to help raise their self-esteem?