Prepositions in on

1. Prepositions in-on
We use preposition in:
-When an object is inside of something.
-For years, months, centuries and long
periods.

2. Examples:
-The keys are in the desk.
-We finish the high school in 2017.
-They celebrate their anniversary in May.
-Argentina will progress in the next century.
-The mankind will travel to Jupiter in the future.

3. Prepositions in-on
We use preposition on:
-To express a surface of something.
-Days and dates.

4. Examples:
-The ball is on the table.
-Her birthday is on July the 5th.
-We see us on Tuesday.
- His birthday is on New Year’s Eve.