In one my novels, a separate section is given as Points to Ponder Over. However, no phrasal verb as such (ponder over) really exists. By Oxford dictionary, ponder is a transitive verb. So it cannot be used without as object, so just to have an object, an over(a preposition) has been added?
In oxford dictionary, an example is given as
She sat pondering over her problem.
But I wonder, why not use just ponder when no such phrasal verb ponder over really exists.
Also sometimes phrasal verbs and verbs have the same meaning, eg- follow and follow up, add and add up,etc. In that case, which should I prefer to speak/write?