[General] examining of four sentences only

[vil]

Dear teacher,

Would you be kind enough to check out the plausibility of the following sentences?

Though I have not seen her for years, yet I remember her well.

I see him every day but I have never spoken to him though.

It is worth trying (even) though we may fail.

In spite of the fact that he gave promise officially he did not come though.

Thank you for your efforts.

Regards,

V.

 

[billmcd]

#1 is OK but you don't need "yet".
#2 "though" is not necessary because it is redundant in this sentence with "but" OR you could replace "but" with "though".
#3 is OK with or without "even".
#4 Suggest: "In spite of the fact that, officially, he promised, he did not come". OR "Though officially he promised to come, he did not"