There are times when the verb "to be" is included in the context even if it is not writen. Can you tell me when I don't need to write it?

Thank you so much! ^^

Thank you so much! ^^

Thank u! Thank u! Thank u! :D

 we usually use 我 ， 你， 他， as I  ,you and he. Then we add 们 follow them, 我们、你们、他们， they become to we, you guys and they.  or you can add 的， they become to my , your and his