in these sentences if you are using singular noun or a pronoun then there 'has' will be used and on the other hand if you are using plural noun or pronoun in the sentence then you need to use the helping verb 'have"

use of has to/ have to jab kisi bhi sentence ke last main :- padta hai /padti hai aa jaye (1)"have" with I,we you ,they ,plural noun or pronoun (2)"has"with He ,She ,It singular noun or pronoun for example :- mujhe rojana apne kapde dhone padte . :-I have to wash my clothes everyday.

1.--a person who works in slaughter house where animals ara cut into pieces 2.--a person who sells refreshments,newspapers etc in the rails or in movie theater

1-I am lost = Main kho chuka hun/main gum ho gaya hun 2-I have lost = Maine kho diya hai 3-I have been lost = Mujhe khoya ja chuka hai mtlb somebody made me lose

I have forgotten the way -main gum ho chuka hu