instruct and the preposition "in"

[kjc0123]

I know that in the following sentence, the word "instruct" means "teach" but don't know why it is used with the preposition "in". I guess that there is something different from "teach" in "instruct". What is the difference with regard to the reason why the preposition "in" is used?

Private teachers instructed the daughters of prosperous Philadelphians in French, music, dancing, painting, singing, grammar and sometimes even bookkeeping.

[New Forester]

I think the answer probably is (as so often in English): that's just how it is.

 

The verb teach can operate either on the subject taught, or on the person being taught.  The verb instruct operates only on the person being instructed.

 

For example, you can teach a class of children or you can teach music.  Combining the two, you can teach children music or you can teach music to children.

 

However, using the word instruct,  you can only instruct children, you cannot instruct music.  To say what the topic is you must say you instruct children in music.  I'm not sure why in is the preposition in this case (the choice of preposition often appears random -- for example, the action of writing in the spaces of a form can be called filling it up, filling it out or filling it in).  I think in implies that the action is within the topic -- other similar verbs (such as educate) would also use in.

 

I'm not sure what the technical term is for these two kinds of verbs -- I expect someone else will know.