Suffixes

A suffix is a morpheme added to the end of a base.  There are two types of suffixes: inflectional and derivational.  An inflectional suffix changes the tense in a verb (e.g., -ed), can make a noun plural or possessive (e.g., -s), or can be used to express a comparison (e.g., -est).  Derivational suffixes can change the part of speech (e.g., -less, -ment).  “Inflectional suffixes are the most frequently occurring suffixes in school reading materials, while derivational suffixes appear in less than a quarter of all the words that contain suffixes (White et al., 1989)” (Diamond & Gutlohn, 2006, p. 78).

As recommended with prefixes, introduce suffixes with known Anglo-Saxon bases during initial instruction.  Provide words such as landed, spelled, and cats.  This type of scaffolded instruction better enables students to understand a suffix within the context of known bases.  

Consider teaching the most common suffixes first, as they have the greatest implication for reading and writing.  According to Henry (2010) and Diamond and Gutlohn (2006), four suffixes account for 65% of common suffixed words:  

1. -s               Meaning: plural                                 Example words: cats, balls
2. -es             Meaning: plural                                 Example words: boxes, churches
3. -ed             Meaning: past tense                         Example words: dropped, spelled
4. -ing            Meaning: verb, present participle     Example words: running, dancing

Beginning with these high-utility suffixes allows students ample opportunities to interact with them throughout a variety of contexts.

Instruction in suffixes can begin with young students.  Kindergarten children know the difference in meaning between cat and cats.  As students later begin to read and write suffixes, keep the following in mind:

• Suffix -ed has three sounds (/id/, /d/, /t/) when used as a past-tense verb.  Students need to understand the rules related to each sound.  This knowledge will create greater success with decoding and encoding suffix -ed words. 
• When adding suffixes to words, students need to understand the “Three Great Rules.”  (Consider taking IMSE OG Comprehensive course to learn more about orthography.)

Also, remember to have students make a morpheme card each time a new morpheme concept is taught.