1．celebrate后面接sth (eg. Christmas / a New Year /one’s birthday / marriage /a wedding / a victory)。

2．congratulate后面只能接sb。如果表达"因为某事而祝贺某人"时我们通常用"congratulate sb on / upon sth"或“offer one’s congratulations on / upon sth”。

另外还有一个区别是：celebrate译成"庆祝"，仪式较隆重，而congratulate译成"祝贺",一般只是口头表达一下而已。

   We celebrated the New Year with a dance party.我们举行跳舞晚会庆祝新年。
   I congratulated my friend on her birthday.我向女友祝贺生日。
   Let me congratulate you on the birth of your daughter.我祝贺你喜获千金。
   You really should congratulate yourself on your appearance.你真该为自己的外表而庆幸。