this morning
fixed phr.. A1 Beginner Oxford
fixed phr.. The morning of the day that is happening now.
fixed phr.. A deictic temporal adverbial phrase referring to the morning of the current day.
I went for a run this morning.
She had a very important meeting with her team this morning to plan the next quarter.
The strange melancholy that had descended upon him this morning persisted throughout the day, casting a pall over his usual optimism.
Usage
This phrase is used without a preposition like 'in' or 'on'.
Teaching tip
Contrast 'this morning' (referring to the past part of today) with 'in the morning' (which usually refers to tomorrow morning or a general future morning).
Pitfall
I saw her on this morning.I saw her this morning.Temporal phrases with 'this', 'next', 'last', or 'every' do not take a preposition.