(+ on) to express one's pleasure to (somebody) at their success or good fortune
He congratulated her on her promotion
congratulation /-ʹlaysh(ə)n/ noun
congratulator noun
congratulatory /-lət(ə)ri/ adj
[Latin congratulatus, past part. of congratulari to wish joy, from con- + gratulari to show joy, from gratus pleasing]