Example sentence:
I cut another bit of meat and nibble at/on it.
What's the correct preposition? I aske because Google shows that both are used.
Example sentence:
I cut another bit of meat and nibble at/on it.
What's the correct preposition? I aske because Google shows that both are used.
It is not really necessary to use either preposition. This sentence is fine without a preposition:
I cut another bit of meat and nibble it.
If I wanted to focus on the comsumption of something, I would use on, in the same way as one can dine on something.
If I wanted to focus on the effect it has on the thing that is being nibbled- the removal of small pieces from the edge or surface of it- I would use at, in the same way as a cat might scratch at a door.
Although both the idioms "to nibble at something" and "to nibble on something" have the meaning of eating by small bites, in the former that something is always some kind of food, whereas in the latter it may also be something that you bite but not break its surface.
Examples:
The rabbit nibbled on/at a carrot.
Fish were nibbling at the bait
He nibbled nervously on his fingernail.
So regarding your sentence, there's no difference; although I'd prefer "nibble at".
If you eat something slowly or with small bites, you can use the verb nibble without a preposition or with the preposition at/on, without any difference in meaning: So you can say:
I cut another bit of meat and nibbled it.
I cut another bit of meat and nibbled at/on it.
Besides, you can also use nibble, nibble at, or nibble on, when you gently bite a part of someone's body. For example:
He nibbled/nibbled at/nibbled on her neck affectionately.
When you show a slight interest in an idea or offer, you can use "nibble at" as follows:
I nibbled at the idea.
The nibble with the preposition "at" is also used to convey the sense that something affects somethiny or causes something to disappear gradually as follIows:
The police have been nibbling at crime in the city for 2 years.
Inflation is nibbling at our purchasing power.