I've noted that sometimes there is a comma before the word 'too'. I am a little confused as to when to apply it. I understand we do not add it when we are just affirming agreement between two things or people concerning one specific condition. Example: -I like cake. -I like cake too. However, I am not sure if there is a rule about it when we are using 'too' as exchangeable with 'also'. Example: "I found the test very difficult. The questions were of higher-level than I thought they would be. There was very little time to answer too." Is that correct, or should a comma be placed before 'too'? Thanks for the help.