Mourning is grief, especially after a death, while morning is the start of the day. Memory hook: mourning has a u like mourn and you feeling the loss; morning is the plain start of the day.
The core difference
Mourning is the act of grieving, whereas morning is the early part of the day.
- mourning — grieving after a death: The nation observed a week of mourning after the disaster.
- morning — the early part of the day: She goes for a run every morning before work.
- mourning — traditional grieving clothes: Her mourning consisted of a simple black dress and veil.
How to tell them apart
In many accents the two sound the same, which is why the mistake is common in cards, headlines and social posts. Ask whether the sentence is about sadness over a loss or about a time of day. Phrases such as good morning and morning coffee always use morning.
Try this: mourning comes from the verb mourn, so if you can swap in grieving, keep the u. If you can swap in early in the day, drop it.