SpeakUP Academy
Descubre tu nivel
HomeSuffixes-stone
ESEN

Suffix · forms nouns

-stone

Forms compounds naming types of stone, places, or concepts involving permanence and foundation: milestone, cornerstone, tombstone, keystone, limestone.

In Spanish: piedra / hitoLiterary

Written by Bryan López, English teacher · Updated June 2026

What does -stone build?

-stone keeps the meaning of "stone" (rock, hard mineral) and creates two broad groups of compounds: Literal stones and materials: • limestone = calcareous rock (lime + stone) • cobblestone = rounded paving stone • sandstone = sedimentary rock made of sand • flintstone = hard rock used to make fire • grindstone = stone wheel used for sharpening Metaphorical concepts: • milestone = a key point of reference (from Roman mile-marker stones) • cornerstone = the essential foundation of something • tombstone = a stone marking a grave • keystone = the central stone of an arch; the central element of a system • stepping stone = something that leads toward a goal

Milestone and cornerstone in formal English

"Milestone" is indispensable in academic, business, and journalistic English: "a milestone in the history of science," "reaching a key milestone," "a milestone agreement." Originally, it was a stone marking each Roman mile; today it marks any event that signals a significant before-and-after. "Cornerstone" names the most fundamental element on which something rests: "the cornerstone of democracy," "a cornerstone of the peace agreement," "education is the cornerstone of development." In architecture, the cornerstone is the first stone laid, setting the alignment for everything that follows.

Grindstone: the idiom of hard work

"Keep your nose to the grindstone" is one of the most recognized English idioms: it means to work without stopping, head down, focused on the task — like a craftsman leaning close to a grinding wheel. "Stepping stone" (something that helps you advance toward a goal) is also very common: "This job is just a stepping stone to a bigger career." It conveys progress through intermediate stages.

How it is pronounced

-stone/stoʊn/ · sounds like "stone"

Tap the button to hear how the ending sounds. Each word in the table has its own audio.

Examples

Base word
With -stone
In a phrase
  • milemilestoneThe moon landing was a milestone in human history.
  • cornercornerstoneFree speech is the cornerstone of a democratic society.
  • tombtombstoneHer name was carved into a simple tombstone.
  • keykeystoneTrust is the keystone of any successful relationship.
  • limelimestoneThe cliffs are made of white limestone.
  • cobblecobblestoneWe walked down a narrow cobblestone street.
  • grindgrindstoneHe kept his nose to the grindstone for years.
  • stepstepping stoneEach small success is a stepping stone to greatness.

Common mistakes

a milestone person / a milestone idea
a milestone event / a milestone achievement

"Milestone" works as a pre-noun adjective only with events, achievements, or agreements: "a milestone moment," "a milestone ruling." Not used with people or abstract ideas.

the cornerstone is education
education is the cornerstone

Natural word order: "X is the cornerstone of Y." Reversing it sounds awkward.

A trick to remember it

In academic and formal English, "milestone" and "cornerstone" carry real weight. Learn these fixed phrases: "reach a milestone," "mark a milestone," "the cornerstone of," "a cornerstone principle," "a stepping stone to." Each one signals polished, precise writing.

Practise what you learned

Exercise 1 · Form the word

Fill in: "The discovery of penicillin was a ___ in medical history." (key reference point)

Hint: Mile + stone: what marks a significant point of reference.

Exercise 2 · Pick the right one

"The cornerstone of democracy is free speech." What does "cornerstone" mean here?

Exercise 3 · Form the word

Fill in: "This internship is a great ___ to a career in medicine." (something that leads toward a goal)

Hint: A stone that helps you step forward.

Frequently asked questions

What does the suffix -stone mean in English?

The suffix -stone forms compounds naming types of stone, places, or concepts involving permanence and foundation: milestone, cornerstone, tombstone, keystone, limestone. In Spanish it usually maps to piedra / hito.

How do you pronounce -stone?

The ending -stone is pronounced /stoʊn/ · sounds like "stone". For example, "milestone".

Can you give an example of a word with -stone?

"mile" becomes "milestone". It is a typical example of the -stone suffix.

Other useful suffixes

  • -craft

    Forms compounds naming a specialized skill, art, or type of vehicle: aircraft, spacecraft, witchcraft, stagecraft, statecraft, wordcraft.

  • -mark

    Forms compounds naming marks, signs, or reference points: hallmark, benchmark, landmark, trademark, earmark, watermark.

  • -wise

    From Old English "wise" (manner, way): converts nouns and adjectives into adverbs of manner. Otherwise, likewise, clockwise, contrariwise, streetwise.

Learn every English suffix

-tion, -ness, -ful, -ly, -able... every ending you need to understand thousands of words at once.

View all suffixes
SpeakUP Academy

Aprende

  • Lecciones gratis
  • Test de nivel
  • Glosario
  • Falsos amigos

SpeakUP

  • Nosotros
  • Iniciar sesión

Legal

  • Términos
  • Privacidad
© 2026 SpeakUP Academy. Todos los derechos reservados.