What is the difference between sufficient and adequate and enough and ample ?Feel free to just provide example sentences.

Sufficient and adequate mean the same thing. They both mean that you have the amount you need of something. If we were to represent these words with a mathematical statement, it would look like: (Amount is equal to need)

Enough means that you have the amount you need or more than the amount you need of something. Used like this, it is not specific. If we were to make this word into a mathematical inequality, it would take the form of (amount is greater than or equal to need). If you say "Just enough" it signifies that you have exactly the right amount of something. In this case, it would be (amount is equal to need)


Ample means that you have specifically more than enough of something, most of the time in a good way. (Amount is greater than need)
Example: "I had ample time to write the essay, so I wasn't too stressed about it."

NOTE: In speech, almost no one says "ample". I've only seen it in old books.

Recap:

Sufficient/Adequate:
(Amount = Need)

Enough:
(Amount ≥ Need)

Just enough:
(Amount = Need)

Ample:
(Amount > Need)