Educational worksheet for identifying prefixes, root words, and suffixes in various words.

To solve the problem, we need to identify the prefix, root word, and suffix for each given word. Here's a breakdown of the solution:

Definitions:

- Prefix: A group of letters added to the beginning of a root word to change its meaning.
- Root Word: The base part of a word that carries the primary meaning.
- Suffix: A group of letters added to the end of a root word to change its meaning or form.

Solution:

| WORDS | PREFIX | ROOT WORD | SUFFIX |
|--------------|----------|------------|-----------|
| preheat | pre- | heat | - |
| unkind | un- | kind | - |
| undersea | under- | sea | - |
| submarine | sub- | marine | - |
| comfortable | comfort- | able | - |
| wonderful | wonder- | ful | - |
| defrost | de- | frost | - |
| overlook | over- | look | - |
| quickly | quick- | ly | - |
| breathless | breath- | less | - |
| tallest | tall- | est | - |
| worthless | worth- | less | - |
| replay | re- | play | - |
| ungrateful | un- | grateful | - |
| underground | under- | ground | - |
| tallest | tall- | est | - |
| unhappy | un- | happy | - |
| preschool | pre- | school | - |
| disappear | dis- | appear | - |

Explanation:

1. preheat:
- Prefix: "pre-" (meaning "before")
- Root Word: "heat"
- Suffix: None

2. unkind:
- Prefix: "un-" (meaning "not")
- Root Word: "kind"
- Suffix: None

3. undersea:
- Prefix: "under-" (meaning "below")
- Root Word: "sea"
- Suffix: None

4. submarine:
- Prefix: "sub-" (meaning "under")
- Root Word: "marine" (related to the sea)
- Suffix: None

5. comfortable:
- Prefix: "comfort-" (from "comfort")
- Root Word: "able" (indicating ability or capability)
- Suffix: None

6. wonderful:
- Prefix: "wonder-" (from "wonder")
- Root Word: "ful" (indicating full of something)
- Suffix: None

7. defrost:
- Prefix: "de-" (meaning "reverse" or "undo")
- Root Word: "frost"
- Suffix: None

8. overlook:
- Prefix: "over-" (meaning "above" or "beyond")
- Root Word: "look"
- Suffix: None

9. quickly:
- Prefix: "quick-" (from "quick")
- Root Word: "ly" (indicating manner or adverbial form)
- Suffix: None

10. breathless:
- Prefix: "breath-" (from "breath")
- Root Word: "less" (indicating absence)
- Suffix: None

11. tallest:
- Prefix: "tall-" (from "tall")
- Root Word: "est" (superlative ending)
- Suffix: None

12. worthless:
- Prefix: "worth-" (from "worth")
- Root Word: "less" (indicating absence)
- Suffix: None

13. replay:
- Prefix: "re-" (meaning "again")
- Root Word: "play"
- Suffix: None

14. ungrateful:
- Prefix: "un-" (meaning "not")
- Root Word: "grateful"
- Suffix: None

15. underground:
- Prefix: "under-" (meaning "below")
- Root Word: "ground"
- Suffix: None

16. tallest:
- Prefix: "tall-" (from "tall")
- Root Word: "est" (superlative ending)
- Suffix: None

17. unhappy:
- Prefix: "un-" (meaning "not")
- Root Word: "happy"
- Suffix: None

18. preschool:
- Prefix: "pre-" (meaning "before")
- Root Word: "school"
- Suffix: None

19. disappear:
- Prefix: "dis-" (meaning "away" or "apart")
- Root Word: "appear"
- Suffix: None

Final Answer:

\boxed{
\begin{array}{|c|c|c|c|}
\hline
\text{WORDS} & \text{PREFIX} & \text{ROOT WORD} & \text{SUFFIX} \\
\hline
\text{preheat} & \text{pre-} & \text{heat} & - \\
\hline
\text{unkind} & \text{un-} & \text{kind} & - \\
\hline
\text{undersea} & \text{under-} & \text{sea} & - \\
\hline
\text{submarine} & \text{sub-} & \text{marine} & - \\
\hline
\text{comfortable} & \text{comfort-} & \text{able} & - \\
\hline
\text{wonderful} & \text{wonder-} & \text{ful} & - \\
\hline
\text{defrost} & \text{de-} & \text{frost} & - \\
\hline
\text{overlook} & \text{over-} & \text{look} & - \\
\hline
\text{quickly} & \text{quick-} & \text{ly} & - \\
\hline
\text{breathless} & \text{breath-} & \text{less} & - \\
\hline
\text{tallest} & \text{tall-} & \text{est} & - \\
\hline
\text{worthless} & \text{worth-} & \text{less} & - \\
\hline
\text{replay} & \text{re-} & \text{play} & - \\
\hline
\text{ungrateful} & \text{un-} & \text{grateful} & - \\
\hline
\text{underground} & \text{under-} & \text{ground} & - \\
\hline
\text{tallest} & \text{tall-} & \text{est} & - \\
\hline
\text{unhappy} & \text{un-} & \text{happy} & - \\
\hline
\text{preschool} & \text{pre-} & \text{school} & - \\
\hline
\text{disappear} & \text{dis-} & \text{appear} & - \\
\hline
\end{array}
}