But ngram for impacted him vs impacted on him shows the version without on is much. Nowadays, we often see the word impact being used as a verb. The use of impact as a verb to indicate greater effect seems to have come into use in the 1960s.
Harris hours away from most consequential announcement of her career
Should it always take the preposition on or is it a matter of personal preference?
Is the preposition in grammatical here?
This change has no impact on the system's current beha. Impact (early 17th century) comes from the past form of the same source. Purely aesthetically, i'd prefer impact on, although the transitive form is useful in the passive. This change has no impact in the system's current behaviour.
Is there a grammarians' consensus as to the usage of impact (as a verb)? My question is, should it be always followed by the preposition on? Oxford dictionaries gives the following example: I think we should have used on instead:
Her speech made a profound impact on everyone.