In the TV shows or something, I've come across that kind of sentences. And make me wonder.
why won't say just 'I pat his back'. it's shorter than 'pat him on the back'.
and what situation would people say with the latter sentence 'pat him on the back' and could you give me more examples related to mine?
(I hit him in the eyes.. or I hit his eyes.)
Learn English – the difference between ‘pat him on the back’ and ‘pat his back’
idiomsprepositional-phrasesprepositions
Best Answer
Looking at your examples, I feel that you are talking about some actions to be done on others.
Pat him on the back will be used with the preposition 'on' for a solid reason: it is an idiom and we use idioms as they are.
When you are performing some action on someone's organ, it has to be specified. Patting happens on someone's shoulder; hitting happens in someone's eyes considering that eyes were open then.
The safest way is to refer some dictionary and check whether it's an idiom/phrase. In other cases, I feel that the preposition is to be mentioned. Another example is kick on his ____ over kick his ____.