I was making a table of the sentence "You must/have to see it." (
"You see it.") in different tenses and moods in German with the English equivalent.
I ended up writing these three sentences down (in English) and was unsure about what tense they were in or if they could be considered valid sentences.
(1) You will have had to see it.
(2) You will have to have seen it.
(3) You will have had to have seen it.
I believe that (1) is future perfect but I have no idea about (2) and (3).
I'm a native English speaker and so I have never had a formal teaching of English grammar. As an example I will have used future perfect many times in my life but I have only recently known of it's existence! Most of what I have learnt is from the perspective of learning German.