<p>I know where must refer to an actual loccation, and which refers to objects, but when do you know exactly when to use it and what is the difference bewtween on which and in which?</p>
<p>The difference between "on which" and "in which" is the difference between "on" and "in," but I assume that you know both of those words, so it's kind of hard to give a better answer to your question without some example sentences which confuse you.</p>
<p>where refers to a specific place (e.g. in a world where there is tons of poverty). in which refers to a situation (e.g. The scientists performed an experiment in which they found that tapeworms can grow over 20 feet). on which refers to a specific item/thing (e.g. On which team did he play for?).</p>
<p>You wouldn't say "On which team did he play for?" You would say either "on which team did he play" or "for which team did he play?" You can't end a sentence with a preposition ("for") and using "on which" and "for" is repetitive.</p>