Acts of service are not when meet your partners demands (nobody feels like doing things they are forced to do!), but when you do something out of your own to keep her happy. If your wife regularly complains for example that you never want to buy the groceries for her or are prepared to bath the kids, it’s then possible that her love language is acts of service. “Your partner’s criticism of your behaviour is a clue to their primary love language. People are inclined to criticize their partner on the area where they feel the deepest emotional need. Their criticism is a cry for love,” explains Gary.

Source:  Intimacy for us