1) At the very last day of the year, I will usually do a comtemplation/reflection on what I have achieved and what I failed to achieve it that year.
2) You must know what and when something has to be done. For example, when is time to play you play, when is time study, you have to study.
3) After the argument I went back to my room and reflected/contemplated/brood over and anyalyzed about the argument we had. After reflection/contemplation/brooding over and analyzed it, I think I was in the wrong.
Are the highligted words used correctly in the above sentences. If no, can somebody help me correct it. Thanks.