Right preposition

Either preposition can be used. I prefer "in."

We want an expert in human health.

AlpheccaStarsEither preposition can be used. I prefer "in."We want an expert in human health.

Thanks for your help.

So both prepositions are possible, with preference for 'in', in all similar sentences. Have I understood correctly?

But 'at' not 'in or on' is used when we say: he is good 'at' writing. Am I right?

AnonymousSo both prepositions are possible, with preference for 'in', in all similar sentences

Here are two contrasting cases.

He is an expert on the subject of paleoarchaeology.
He is an expert in paleoarchaeology.

Anonymouswe say: he is good 'at' writing. Am I right?

Yes. "good at" is the common expression.

AlpheccaStars AnonymousSo both prepositions are possible, with preference for 'in', in all similar sentencesHere are two contrasting cases.He is an expert on the subject of paleoarchaeology.He is an expert in paleoarchaeology.Anonymouswe say: he is good 'at' writing. Am I right?Yes. "good at" is the common expression.

Thank you. But what do you mean by two con

AnonymousThank you. But what do you mean by two contrasting cases?

The sentences have same meaning and one naturally uses "in", while the other uses "on."

You can see here that the majority of the writers use "expert in physics," but there are a few cases of "expert on physics."

AlpheccaStarsI hope that makes my previous post clearer.

Thank you very much. That was very clear.

I understand that either proposition is possible but one is favored in each case, as you have shown. Right?

AlpheccaStars But there are a very small number that use "in the subject of X". (eg. Cyril seems to be uninterested in th

Anonymousin this example, which you have given with ‘in':Cyril seems to be uninterested on the subject of the thanksgiving.

The example was from the ngram viewer.

In this case, you have to parse it differently:
He is [( un)interested in] the subject.

Interested in is the phrasal verb. "Interested on" is not.

AlpheccaStarsIn this case, you have to parse it differently:He is [( un)interested in] the subject.Interested in is the phrasal verb. "Interested on" is not.

I got it. So this can be seen as an exception in which because ‘interested’ takes ‘in’ not ‘on’. Have I explained correctly?

Also, is everything else I said in the previous post correct regarding

AlpheccaStars Anonymousin this example, which you have given with ‘in':Cyril seems to be uninterested on the subject of the thanksgiving.The example was from the ngram viewer.In this case, you have to parse it differently:He is [( un)interested in] the subject.Interested in is the phrasal verb. "Interested on" is not.

Hi AStars, would you confirm my previous p

AnonymousSo this can be seen as an exception in which because ‘interested’ takes ‘in’ not ‘on’. Have I explained correctly?

Yes. There are other phrasal verbs, and some with "in" and others with "on." You cannot substitute the prepositions in phrasal verbs.

AnonymousAlso, is everything else I said in the previous post correct