5RW1.2 Use word origins to determine
the meaning of unknown words.
5RW1.4 Know abstract, derived roots
and affixes from Greek and Latin
and use this knowledge to analyze
the meaning of complex words
(e.g., controversial).
Roots, Affixes,
and Word Origins
Introduction
In this lesson, you will learn about how to figure out the meanings of words that
have a base word and an affix. An affix is a word part, and a base word is a
word that you can add affixes to. Base words and affixes have meanings. Like
blocks that change size as you join them, a base word’s meaning changes when
you add an affix.
Prefixes are affixes added to the beginning of a word. The word distrust has the
prefix dis- added to the base word trust. Dis- means “the opposite of,” so distrust
means “the opposite of trust.” If you distrust someone, you don’t believe that he
or she is honest.
Suffixes are affixes added to the end of a word. The word purposeful has the
suffix -ful added to the base word purpose. Purposeful means “full of purpose”
because -ful means “full of.” A suffix may also change the part of speech of the
root word, which means the word will be used differently in a sentence. For
When you see a base word with an affix, think about the meaning of each part.
Put the meanings together to figure out what the word means.
Finally, you should understand that many words in the English language come
from other languages. Many of these words, or roots, come from Latin or Greek.
For example, the root aqu- comes from the Latin word aqua, which means
“water.” You can see how this root is used in words such as aquarium.
Putting Words Together
Prefix
+
Base Word
multi
+
color
un
+
+
Suffix
=
New Word
=
multicolor
govern
+
ment
=
government
watch
+
able
=
unwatchable
©
Curriculum Associates, LLC California i-Ready Instruction
example, purpose is a noun, but purposeful is an adjective.
Roots, Affixes, and Word Origins
1
5RW1.2, 5RW1.4
Modeled Instruction
Read this passage. Then fill in the blanks to answer the question below.
Hot Pepper Lab
1 Rafiq is visiting his mother, Dr. Ahmed, at her lab. She is developing a
powerful spray to ward off insects. The spray is made of hot peppers, because
scientists have found that many insects dislike hot pepper.
2 First, Dr. Ahmed dries the peppers. Then she grinds the dried peppers into
a fine dust. Next, Dr. Ahmed takes a small sample and makes a slide for the
microscope. She views the pepper cells under the microscope, recording her
observations in a journal. After that, she tests the pepper powder with litmus
paper. Don’t worry—she doesn’t have to taste it to find out if it will work!
In paragraph 1, what does powerful mean?
▶▶ When you see a longer word, look for word parts you know. You can put these
parts together to figure out the meaning of the word.
▶▶ What is the base word in powerful? The base word is ,
which means “strength.”
, which means “full of.”
.”
ANSWER: The word powerful means .
A powerful spray would probably work well for keeping insects away.
Try It
Reread the passage to answer the question.
The word microscope comes from Greek words for “small” and
“look at.” Based on this information, what is a microscope?
©
Curriculum Associates, LLC California i-Ready Instruction
▶▶ What is the suffix in the word? The suffix is ▶▶ The base word + the suffix means “ Roots, Affixes, and Word Origins
2
5RW1.2, 5RW1.4
Modeled Instruction
Read this sentence. Then fill in the blanks to answer the question below.
The florist arranged the pink roses in a light blue vase.
In which word does ist mean the same as it does in the word florist?
A enlist
B dentist
C listen
D misty
In which word does ist mean the same as it does in the word florist?
▶▶ The suffix -ist means the “doer” or “dealer” of something. From the sentence,
you can tell that a florist is someone who does things with ,
such as arranging roses in a vase.
▶▶ Look back at the answer choices. Is there another “doer” on the list? The only
other “doer” on the list is a things with teeth.
, which is someone who does
Try It
Reread the sentence above to answer the question.
The word arbor comes from the Latin word for “tree.” Based on
this information, what would the word arborist mean?
©
Curriculum Associates, LLC California i-Ready Instruction
ANSWER: Choice Roots, Affixes, and Word Origins
3
5RW1.2, 5RW1.4
Guided Practice
Think About It
Read the passage. Use each Think About It to guide your reading.
Unfair at the Fair
What is the author’s
reaction to the fair?
If something is the
biggest of its kind, is it
common or uncommon?
1 I am so upset about what happened today at the fair. This
morning I was very excited to get to the State Fair to see if I
had won a prize for my entry. I returned home very
disappointed by the turn of events.
2 Every year the fair has a contest for the biggest things—like
the biggest pumpkin or the biggest pig. Some of the biggest
things are very unusual, like the biggest wheel of cheese.
I had always wanted to enter with something cool and recordbreaking, but I just needed to decide on what it would be.
4 Since then, I have been collecting bits and pieces of string
every chance I get and adding them to my growing ball.
I tightly wind each new piece of string onto the ball so the ball
is neat and compact. I do not cheat. I only let myself use pieces
of string that I find—a little piece here, a little piece there.
What happened that the
author thinks isn’t fair?
Why does he think that
the string company has
an unfair advantage?
What is the author afraid
might happen at next
year’s fair?
5 That is why what happened seems so unfair to me! A group
of people at a string company decided to enter the contest, and
they won! Some people think that it was fair for the string
company to enter. I disagree. How hard is it for a machine at
the string factory to wind string to make a huge ball? I think
the string company had an unfair advantage in the competition.
6 I will write a letter to the State Fair committee, and we will
see what happens. In the meantime, I will keep adding bits and
pieces to my ball of string. It will be my misfortune if those
people from the string company enter the contest again
next year.
©
Curriculum Associates, LLC California i-Ready Instruction
3 Then, a few years ago, someone entered a ball of string into
the “biggest things” contest. The ball was three feet tall and
three feet wide. I will never forget when I first saw it. I knew
right then and there—that was exactly what I wanted to do.
I dreamed of breaking the State Fair record with an even bigger
ball of string—the biggest ball of string anyone had ever seen!
Roots, Affixes, and Word Origins
4
5RW1.2, 5RW1.4
Guided Practice
Hints
Which answer choice
makes the most sense
in the sentence if you
put it in front of the
word usual?
Use the Hints to answer the questions below. Circle the correct
answers and provide supporting details from the passage.
1 Read this sentence from the passage.
Some of the biggest things are very unusual, like the
biggest wheel of cheese.
The prefix un- in the word unusual means
A below.
B nearly.
C completely.
D not.
Supporting Details: There many different
kinds of factories.
What do they have
©
Curriculum Associates, LLC California i-Ready Instruction
in common?
2 Read this sentence.
How hard is it for the machine at the string factory to wind
string to make a huge ball?
The origin of the word factory is the Latin word factor, meaning
A spinner, weaver.
B sayer, speaker.
C doer, maker.
D buyer, seller.
Supporting Details: The prefix mis- means
“not.” Which answer
choice best matches
with “not having luck”?
With your partner,
share and discuss
your answers and
supporting details.
Roots, Affixes, and Word Origins
3 The origin of the word misfortune is the Latin root fortune,
meaning “luck.” What does misfortune mean as it is used in
the passage?
A mistake
B success
C bad luck
D good luck
Supporting Details: 5
5RW1.2, 5RW1.4