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-" (related to comfort)
- Root Word: "able" (capable of)
- Suffix: None

6. wonderful:
- Prefix: "wonder-" (related to wonder)
- Root Word: "ful" (full of)
- Suffix: None

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

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

9. quickly:
- Prefix: "quick-" (related to speed)
- Root Word: "ly" (adverbial suffix)
- Suffix: None

10. breathless:
- Prefix: "breath-" (related to breathing)
- Root Word: "less" (without)
- Suffix: None

11. tallest:
- Prefix: "tall-" (related to height)
- Root Word: "est" (superlative suffix)
- Suffix: None

12. worthless:
- Prefix: "worth-" (related to value)
- Root Word: "less" (without)
- 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-" (related to height)
- Root Word: "est" (superlative suffix)
- 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}
}