In 1994, INSOO KIM BERG introduced the concept of the indirect compliment. Complimenting indirectly means that you invite the other person through a question to describe what was good about what he or she has done and what has worked well. An example of an indirect compliment is: “Wow, how did you manage to finish that task so quickly?"). I like to call such kinds of questions AFFIRMING QUESTIONS. It is also possible to include the perspective of other people in compliments. An example may be: “What do your colleagues appreciate in how you work?” An advantage of complimenting through questions is that you activate the other person. Also, there is less chance that he or she will feel embarrassed or will turn down the compliment ("It was nothing special"). Instead you challenge the other person and make him or her reflect (“Actually, how did I do that.... let's see.....?”).
Also read: Learning to compliment effectively