There is two High School is our village. 

= There are two High School in our village.

There lived a certain king. 

There was dust on the floor.

They came home while I was studying.

They elected him captain.   = He was elected captain by them.

They elected me secretary. (Passive) = I was elected secretary by them.

They had dug the pond=The pond had been dug by them.

They have come yesterday. = They came yesterday.

They look forward to receiving.

They looked at the picture=The picture was looked at by them.

They said that they had watched the movie already (direct) 

= They said, "We have already watched the movie."

This culture is alien to our society.

This is a unique case.

This is a unique case

This is the better of the two.