What this suffix does
-kept evaluates how well something is maintained: well-kept, poorly-kept. "a well-kept secret".

Suffix · forms adjectives
Judges how well something is maintained: well-kept (neat, well-maintained) versus poorly-kept (neglected).
Written by Bryan López, English teacher · Updated
-kept evaluates how well something is maintained: well-kept, poorly-kept. "a well-kept secret".
Adverb + kept.
This is not a productive rule you can apply freely: it is a closed set of fixed expressions. Learn them one by one as set phrases.
-kept
Tap the button to hear how the ending sounds. Each word in the table has its own audio.
"Well-kept" describes ongoing maintenance rather than newness. A well-kept house is not one that has just been renovated — it is one that has been consistently and carefully maintained so that it retains its quality over time. The "keeping" is an active, continuous process rather than a single event.
The phrase "well-kept secret" can occasionally be used ironically (something is "the best-kept secret in the industry" meaning it is not widely appreciated but should be — i.e., a hidden gem). But the primary meaning is positive: a well-kept secret is one that has been successfully kept — it has not leaked. Context clarifies which sense is in use.
A trick to remember it
well-kept = "well maintained", from "keep". Applies to physical things (a well-kept garden) and to information (a well-kept secret): in both cases, someone "kept" it well.
Exercise 1 · Form the word
Exercise 2 · Pick the right one
"a poorly-kept garden" is a garden that is...
The suffix -kept judges how well something is maintained: well-kept (neat, well-maintained) versus poorly-kept (neglected). In Spanish it usually maps to cuidado / mantenido / conservado.
"well" becomes "well-kept". It is a typical example of the -kept suffix.
Describes how a person, animal, or talent was raised: well-bred (well-mannered) versus ill-bred (badly raised).
Describes someone's manners or conduct: well-mannered (polite) versus ill-mannered (rude).
Describes someone's underlying character: good-natured (kind, easygoing) versus ill-natured (bad-tempered).
-tion, -ness, -ful, -ly, -able... every ending you need to understand thousands of words at once.