"on the morning" is used in a formal sense, to firmly establish when something happened. It is associated with a date or a day relative to an event. It is used in court descriptions, by the police or in writing which wants to establish an exact sequence of events. "On the morning of Monday, April 16, he met with his business associates." "The meeting took place on the morning of the Thursday after the initial agreement." "In the morning" is used to describe something we do informally, or all the time. "I went to classes in the morning." "I usually get most of my work done in the morning." "Saturday, we will be traveling in the morning." It would be used all the time in informal, conversational English.

don't has difference. use "on" what do we go do someday ex: I study on the morning of Monday use "in" what do we go today ex: I study in the morning My native language is not English, but I have some notion, correct me if I'm wrong. I have helped !

Choosing between "in" and "on" can be confusing. Oftentimes, either is correct. Remember to use "on" for specific dates and days. "In" is used with a moment enclosed in time, like "in spring" or "in 2012" or "in January". "On summer nights" is an open-ended time reference, hence the use of "on". "At" is for precise times, like "at night". http://www.italki.com/answers/question/147030.htm

As far as I know the word "morning" is used with the preposition "in", in the morning. If you want to add a day of the week, then you should use "on", on Friday morning.