B. Foundations of Language · Foundations: Speaking, Listening, Words and Fluency

Prefixes for Grade 8: Without, Away, Both, Through, Upon, Below, Change, Beside and Around

B2.1 B2.2 A3.1About 45 minutes

Learning goals

I can peel prefixes off complex words to read and spell them accurately and automatically.
I can use the Grade 8 prefixes a-/an-, ab-, ambi-/amphi-, dia-, epi-, infra-, meta-, para- and peri- to figure out meanings.
I can combine these prefixes with roots I already know to understand words in science, math and other subjects.
I can test whether a word part is really a prefix by checking the meaning.

Words to know

prefix
A word part added to the start of a base or root that changes its meaning.

asymmetrical
Not symmetrical: the two sides don't match.

ambiguous
Able to be understood in more than one way; unclear.

diameter
A straight line through the centre of a circle, from one side to the other.

epicentre
The point on Earth's surface directly above where an earthquake starts.

metamorphosis
A complete change of form, like a caterpillar becoming a butterfly.

perimeter
The distance around the outside of a shape.

Remember from earlier grades

You've collected a lot of prefixes: everyday ones (un-, re-, dis-, pre-, mis-), Grade 4's inter-, trans-, super-, semi-, anti-, Grade 5's number and position prefixes (mono-, poly-, post-, circum-, extra-), Grade 6's bene-, mal-, omni-, hyper-, hypo-, contra-, syn-, and Grade 7's proto-, neo-, retro-, pseudo-, homo-, hetero-, macro-, mega-, equi-. You also know how to peel a word: prefixes off the front, suffixes off the end, find the root, then put it back together and check the meaning.

Grade 8 adds prefixes that show up again and again in high school science, math and English.

Let's start with a puzzle

What do a frog, a hovercraft and some military vehicles have in common? They can all be called amphibious: they can work both on land and in water.

Peel it: amphi- (both) + bi (life, as in biology) + -ous (having). An amphibian like a frog lives a "double life": it usually starts life in water and later can live on land. One prefix, plus a root you already know, and the word explains itself.

A spotted green-brown leopard frog resting half in shallow pond water and half on a muddy bank among lily pads and reeds. — A northern leopard frog, found across Ontario, sitting between water and land. Amphibians like this one live a "double life", which is exactly what the prefix amphi- (both) describes. AI-generated image

Prefix	Means	Examples
a-, an-	not, without (you met it in abiotic in Grade 7)	asymmetrical (not symmetrical), atypical, anonymous (without a name: onym = name), anaerobic (without air or oxygen)
ab-	away, from	abnormal (away from normal), absent, abduct (to lead away: duct = lead), abstain (to hold back from: tain = hold)
ambi-, amphi-	both; around, on both sides	ambidextrous (able to use both hands equally well), ambiguous (can mean two things), amphibian, amphitheatre (seats around the stage)
dia-	through, across	diameter (measure across), diagonal (across from corner to corner), dialogue (talk back and forth between people), diagnosis (knowing through examination)
epi-	upon, on, over, after	epidermis (the outer layer of skin, on top of the dermis), epicentre, epidemic (spreading upon the people: dem = people), epilogue (a section after the end of a story)
infra-	below, beneath	infrared (light just below red, which we can't see), infrastructure (the underlying systems: roads, bridges, pipes, power lines)
meta-	change; beyond, about	metamorphosis (change of shape), metamorphic rock (rock changed by heat and pressure), metaphor (carrying meaning across), metacognition (thinking about your thinking)
para-	beside, alongside	parallel (lines beside each other that never meet), paramedic (works alongside doctors), paraphrase (saying it alongside, in other words), Paralympic Games (held alongside the Olympic Games)
peri-	around	perimeter (measure around), periscope (a tube for looking around or over things, as on a submarine), periodontist (a dentist for the gums around the teeth)

Grade 8 prefixes. Many come from Greek, so they pair with Greek roots you already know: morph, dem, meter, scope, onym, bio.

Peel metamorphosis: meta (change) + morph (shape, form) + osis (process) = a process of changing shape.

Prefixes in your other subjects

Math: the perimeter goes around a shape; a diameter goes across a circle through the centre; a diagonal goes across a polygon from one vertex to a vertex that isn't next to it; parallel lines run beside each other; an asymmetrical shape has no line of symmetry.
Science: plants and animals both have an outer layer of cells called the epidermis; frogs and salamanders are amphibians; anaerobic bacteria can live without oxygen; infrared cameras "see" heat; caterpillars go through metamorphosis.
Geography and history: infrastructure like roads and water pipes shapes where people settle; an epidemic is a disease spreading through many people at the same time.
English: a metaphor, a paraphrase, an epilogue, a dialogue and an ambiguous ending are all terms you'll use in high school English.

Four math words, three prefixes: a perimeter goes around, a diameter and a diagonal go across, and parallel lines run beside each other without meeting.

Worked example

Let's peel some long words

Read and figure out the meaning of: asymmetrical, diagnosis, infrastructure.

a · sym · metr · ical: a- = not; sym- = together, the same (Grade 6); metr = measure; -ical = related to. Symmetrical means the parts measure the same on both sides. So asymmetrical = not symmetrical: the two sides don't match. A maple leaf is close to symmetrical; a crooked branch is asymmetrical.
dia · gnos · is: dia- = through; gnos = know (a Greek cousin of the Latin root cogn from Grade 7); -is = the act of. So a diagnosis = knowing through careful examination: what a doctor does to figure out what's wrong.
infra · struct · ure: infra- = below; struct = build (Grade 4); -ure = the result of (Grade 5). So infrastructure = the built systems underneath a community: roads, bridges, water pipes, power lines.
Check in a sentence: After the ice storm, crews repaired the town's damaged infrastructure. The meaning fits.

asymmetrical = not symmetrical; diagnosis = identifying a problem by careful examination; infrastructure = the basic built systems a community runs on.

Don't over-peel

Some words only look like they have these prefixes. Parachute comes from a word meaning protect against (a fall), not beside. Paradise and parade aren't para- words either. In about, asleep and ahead, the a- doesn't mean not. Period has peri- but its meaning has drifted far from around. Always test: Does the prefix meaning fit the word's real meaning?

Just for fun

Riddle: What do you call a dinosaur that can use both hands equally well?

An ambidextrosaurus. (Not a real dinosaur, but it would be unbeatable at ping-pong.)

Hands-on activity

Prefix hunt and word-building

You need: 18 index cards or scrap paper, a pencil, and a science, math or social studies book (or a news website a parent helps you choose).

On 9 cards, write the prefixes: a/an, ab, ambi/amphi, dia, epi, infra, meta, para, peri.
On 9 cards, write these endings: symmetrical, normal, bian, meter, dermis, red, morphosis, llel, scope.
Shuffle each pile and match them to build 9 real words. Write each word, its meaning, and a sentence using it.
Hunt: spend 10 minutes looking through your book or a news site. Find five words that use a Grade 8 prefix. For each, write the sentence it appeared in and peel it.
Over-peel check: did you find any word that looks like it has one of these prefixes but doesn't? Explain how you know.

What to look for: the full set is asymmetrical, abnormal, amphibian, diameter, epidermis, infrared, metamorphosis, parallel, periscope. (Perimeter is also a real word, but if peri takes meter, dia is left with scope, so periscope and diameter complete the set.) Hunted words should be correctly peeled, and any over-peeled word should be explained by testing the meaning.

Your turn

What does the prefix peri- mean? Use it to explain perimeter.

What does anonymous mean? Show the parts.

Explain ambidextrous.

What is the difference between a diameter and a perimeter?

Why are infrared cameras named that way?

Which prefix means change? Give a science word that uses it.

Explain why a paramedic has that name.

More practice: warm-up

Which prefix means below?

Which prefix means away from?

Which prefix means upon or on?

Which prefixes mean both?

Which prefix means not or without and comes before a vowel as an-?

More practice: on your own

Peel and define abnormal.

A story ends, then has a short section set ten years later. What is that section called? Use the prefix to explain.

Is asleep an example of the prefix a- meaning not? Explain.

What is an amphitheatre, and how does the prefix help?

An earthquake starts deep underground. Where is its epicentre?

Challenge

An ending to a novel is ambiguous. Explain what that means, and why an author might choose it.

Metacognition is part of being a good learner. Use the parts to explain it, and give an example from your own learning.

Invent a new word using a Grade 8 prefix and a root you know, then define it so the meaning follows the parts.

Check your understanding

Quiz

What does asymmetrical mean?

Which word means the distance around a shape?

An amphibian is named for living...

Which prefix means below?

Which word does not really contain the prefix para- meaning beside?

A caterpillar's change into a butterfly is called...

Anonymous means...

For parents and teachers

Big idea (B2.1, B2.2, A3.1): Grade 8 students use consolidated knowledge of morphemes (bases, prefixes and suffixes) to read and spell complex words accurately and automatically, and analyze new words in context, including in other subjects. These prefixes are common in high school science (epidermis, anaerobic, metamorphic), math (perimeter, diameter, parallel) and English (metaphor, epilogue, ambiguous).

How to help at home:

When a long word appears in the news or a recipe, say "Let's peel it" and do it out loud together.
Ask your child to teach you one prefix a day, with two example words.
Connect to their other homework: "Is there a prefix in that math word?"

Common difficulties:

Over-peeling (seeing para- in parachute, a- in asleep). Always test the meaning.
Mixing up dia- and peri-. Memory hook: a diameter goes straight through like a diagonal; a perimeter goes around, like a fence.
Stopping at the prefix. The meaning of the root matters just as much.