庆祝 

Pinyin: qìngzhù 
Meaning：Celebrate  
Sentence：你们今年是怎样庆祝五一节的？How did you celebrate May Day this year?

More: 

庆： 

Pinyin: qìng 
Meaning: Celebrate
Radical: 广
Stokes: 5
Traditional: 慶
Common words/Phrase:
庆典 [qìngdiǎn] 【celebration】 
庆幸 [qìngxìng] 【felicitate】
庆贺 [qìnghè] 【congratulate】
欢庆 [huānqìng] 【festivity】
庆功会 [qìnggōnghuì] 【victory meeting】

祝： 

Pinyin: zhù
Meaning: Wish
Radical: 示
Stokes: 10
Traditional: 祝
Common words/Phrase:
祝福 [zhùfú] 【blessings】 
祝愿 [zhùyuàn] 【wish】
祝词 [zhùcí] 【felicitate】
祝酒 [zhùjiǔ] 【toast】