'hit him on the head' vs. 'hit him over the head'

[Haihao]

Hi,

Could you please help me figure out the difference between 'hit him on the head' and 'hit him over the head'?

Does the latter suggest 'hit him on the top of the head' with 'over' while the former could be anywhere on the head?

Thank you!

Haihao

[Jamie (K)]

When I picture someone being hit on the head with something, I imagine that the weapon has remained intact and in the attacker's hand:

He hit the stranger on the head with a wrench.

If I picture someone being hit over the head with something, I imagine either than the weapon has broken apart on impact, or is very large:

He hit the stranger over the head with a bottle.
He hit the stranger over the head with a two-meter-square sheet of steel.

Sometimes "over" seems to me to indicate that the weapon was flexible:

He hit the stranger over the head with a blackjack.

However, I don't know if other native speakers make any distinction between these two phrases at all.