他并不因这些成就而自夸。 He does not plume himself on these achievements.
对于这一点，我可以豪不自夸地说，在历届美国总统竞选中，没有任何一位候选人象我这样不遗余力地促进统一战线的建立。 On this point, I think I can say without boast, that never in the history of American Presidential campaigns has a candidate gone further than I did in attempting to create a united front.
他自夸自己游泳高明。 He boasts himself a good swimmer.
他喜欢自夸。 He's given to boasting.
他自夸是队里的最佳队员。 He boasted of being/boasted that he was the best player in the team.