Errors in ellipsis occur chiefly with prepositions.

His objection and condoning of the boy's course, seemed to say the least, paradoxical. (The preposition to should come after objection.)

Many men of brilliant parts are crushed by force of circumstances and their genius forever lost to the world.

(Some maintain that the missing verb after genius is are, but such is ungrammatical. In such cases the right verb should be always expressed: as—their genius is forever lost to the world.