I would like to know what is the difference between to thump and to punch?
I punched him and knocked his teeth out.
I thumped him and knocked his teeth out.
"I punched him and knocked his teeth out".
would be correct use in normal speech. It covers all forms of punching, thumping.
"I thumped him and knocked his teeth out"
I would never use thump. My dad might. but even then it would not be as violent or physical as knocking teeth out. It might be a thump on the (upper) arm... I cant imagine using it for the face... mostly just the upper body.
Also - I decked him (and knocked his teeth out) - to knock him down
is to hit someone with a closed fist, most likely in the face, as in boxing.
is to make a dull striking sound produced by hitting something
If you punch someone, that could result in knocking out some teeth. If you thump someone, it is figurative, meaning you hit them somehow to produce a dull sound. 'Thump' is much more commonly understood as a noun, somewhat onomatopoeic, the sound of the word like the sound itself.
To say 'I thumped him and knocked his teeth out' sounds strange because you would not expect a dull sound if teeth were dislodged as a result; you usually don't get a 'thumping' sound from hitting someone in the face hard enough to knock out teeth.
sounds natural (semantically that is).
Thump can refer to a extended bout of violence involving kicking, wrestling, etc., not just a single specific action; whereas punch is more likely to to refer to a single blow with a closed fist. To me there is a connotation of less severity than a beating, about the same as pounding. I remember this usage in children's fiction, but today I think thump has been replaced with beat up.
In my understanding to thump means either that you beat something/someone very hard (e.g. hitting on the table/the wall, because you're angry), or knocking on something very strong (e.g. the door, because you want that someone opens it). Another use for to thump would be if you throw something at the wall/on the floor:
Furthermore to thump could mean that you hit a surface by accident, e.g. running against a glass door that you haven't seen.
To punch means to strike something/someone with your fist and this action is - imho - a bit more aggressively than just thumping. That is, to punch connotes the purpose (or at least being willing) to harm or destroy something/someone while thumping just accidentally results in harm or destruction.