1. Prefixes: Important Word Parts
What is a prefix?
A word part at the end of a word
A word part in the middle of a word
A word part at the beginning of a word

2. Prefixes: Important Word Parts
What is a prefix?
C. A word part at the beginning of a word

3. Prefixes change words!
locked
Can you get into a locked door?

4. Let’s add a prefix
locked un
Can you get into an unlocked door?

5. How did the prefix change meaning of the word?
The prefix was un-. Un- changes the meaning of a word.
un-
Tell your partner how unlocked is different from locked.

6. How did the prefix change meaning of the word?
The prefix un- means “the opposite of” or “not”
So, when the door is unlocked, we could also say that it is “the opposite of locked”, or “not locked”
Adding the prefix changes what the word means

7. Let’s look at another word
pack
What does it mean to pack a suitcase?

8. Let’s look at another word
pack un
What does it mean to unpack a suitcase?

9. Let’s look at another word
pack un
Unpack means “the opposite of” pack

10. Which would you rather eat?
Some questions!
Which would you rather eat?
an unripe apple
a ripe apple

11. Which would you rather eat?
Some questions!
Which would you rather eat?
a ripe apple
Ready to eat
an unripe apple
Not ripe, not ready

12. Which would you rather eat?
Some questions!
Which would you rather eat?
Spoiled food
Unspoiled food

13. Which would you rather eat?
Some questions!
Which would you rather eat?
Spoiled food
Rotten, bad
Unspoiled food
Not rotten, not bad

14. What do you know so far? On your paper, explain what a prefix is
On your paper, explain what a prefix is
Come up with at least three other words that have the prefix “un”

15. Another prefix expensive
What does expensive mean? Talk about it with your partner.
expensive

16. Another prefix in expensivein
expensive
Let’s add the prefix in-. How does this change the meaning of the word?

17. Another prefix in expensivein
expensive
Inexpensive means “not expensive”, or “the opposite of expensive”. The prefix in- can mean the same thing as the prefix un-

18. The prefix in- Sometimes, the prefix in- has the same meaning as un-
Sometimes, the prefix in- has the same meaning as un-
Think about these words:
Inexpensive (not expensive)
Inexperienced (not experienced)
Ineligible (not eligible)

19. Be careful with in-
Does indoor mean “the opposite of door”?

20. Be careful with in- Does indoor mean “the opposite of door”?
Does indoor mean “the opposite of door”?
No! In- does not always have the same meaning as un-. You have to read carefully.

21. What meaning of in- do you see?
invertebrate
Does in- mean “not” in this word?
Or does it mean “inside”?

22. What meaning of in- do you see?
invertebrate
An invertebrate is a creature that does NOT have a backbone. So we see that the meaning of in- is “not”.

23. When in- turns to il- legible: able to be read legible i n
In words that start with l-, the prefix in- gets taken over by the word
legible: able to be read
legible i n

24. When in- turns to il- legible: able to be read il legible
In words that start with l-, the prefix in- gets taken over by the word
legible: able to be read il
legible
not able to be read

25. When in- turns to il- logical: making sense il logical
In words that start with l-, the prefix in- gets taken over by the word
logical: making sense il
logical
not making sense

26. Let’s review Talk about these questions with a partner.
Talk about these questions with a partner.
What is a prefix?
What are some prefixes that we have learned about so far?

27. non- means “not” or “without”
A new prefix
Non- is another prefix.
Like un-,
non- means “not” or “without”

28. Using the prefix non-
The prefix non- is used in a slightly different way from un-
To understand this, let’s look at milk!

29. Using the prefix non-
Milk often has the fat removed to make it healthier
It wouldn’t make sense to use “un-fat” milk, because that would mean that the milk is the opposite of fat

30. Using the prefix non- nonfat
Instead, we use the prefix “non-” to show that the milk has had the fat removed
nonfat

31. Other words with “non-”
What do these words mean?
nonliving
nonessential
nonmetallic
nonsense

32. Prefix or not?
Let’s look for prefixes in some words. Be careful! Not every word will actually have a prefix.
unhappy

33. Prefix or not?
Let’s look for prefixes in some words. Be careful! Not every word will actually have a prefix.
unhappy
This word shows the prefix un-. It means “not happy” or “the opposite of happy”

34. Prefix or not? introduction
There is no prefix here. “Introduction” does not mean “the opposite of troduction”

35. Prefix or not?
none
This does not have a prefix. “None” does not mean “without e” (But it would be pretty funny!

36. Prefix or not?
inedible

37. Prefix or not?
inedible
This word has the prefix in-. It means “not edible” or “not able to be eaten”

38. What have you learned? What is a prefix?
What are some prefixes that mean “not”?
How do prefixes change words?