Personal tools

Introduce: The Prefix bi-

From FreeReading

Jump to: navigation, search
Lesson Type: Introduce
Grade: 2, 3
Group Size: Small Group, Large Group, Whole Class
Length: 15 minutes
Goal: Given the prefix bi-, students will generate and use words that contain bi-.

What to Do


Write the prefix bi- on the board or on a piece of chart paper for the students to see.


1. Introduce the prefix bi- and solicit examples of words that contain bi-.

Today we are going to learn about prefixes. Who knows what a prefix is?

2. Allow time for students to respond.

A prefix is a word part added to the beginning of a word. It changes the meaning of a word. Bi- is a prefix that is used in many words. Bicycle, bifocal, and biweekly are all words that have the prefix bi- in them. Do you know of any other words that have the prefix bi-?

3. As students share, write the responses on the board or on a piece of chart paper. Circle the prefix bi- in each word as it is given.

4. Define the meaning of bi-, as well as words containing the prefix bi-.

Look at the list of words with the prefix bi-. Who knows what bi- means? Bi- means “two.” Look at bicycle. Bicycle means “a vehicle with two wheels.” When the prefix bi- is added to cycle, it changes the meaning of the word. Can anyone tell us what bifocal means? What about biweekly?

5. Solicit the meanings of the remaining words from the first step.


6. Connect words to students’ prior knowledge. Ask students a variety of questions to help them connect their experiences to the words in the list generated in the first step. For example:

Who likes to ride a bicycle?

Do any of your parents wear bifocal glasses?

Can anyone use biweekly in a sentence?


For Advanced Students:

Encourage these students to use each word on the class-created list in a sentence.

Explain how the parts of speech may change when a given prefix is added. In the case of the prefix bi-, the part of speech stays the same. For example, the noun cycle becomes the noun bicycle.

For Struggling Students:

For the students who have difficulty understanding what a prefix is, try presenting the word list above as a series of math equations. For example:

  • bi + cycle = bicycle
  • bi + focal = bifocal
  • bi + weekly = biweekly

For ELL Students:

Point out that some of the same prefixes may exist in their native language. If the prefix is not the same as in English, there may be an equivalent in their native language.

Related activities