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

Explanation:
We need to break each word into three parts:
- Prefix: the beginning part (often changes meaning, like *pre-*, *un-*, *sub-*)
- Root word: the core part that carries the main meaning (e.g., *heat*, *kind*, *sea*)
- Suffix: the ending part (often changes word type or adds meaning, like *-ful*, *-less*, *-able*, *-ness*)

Let’s go word by word and identify each part carefully.

1. preheat → *pre-* (before) + *heat* + no suffix → Prefix: pre, Root: heat, Suffix: (none)
But since the table expects something in every box, and many words have no suffix, we leave suffix blank (as per instructions: “Not all words will have each part”).

2. unkind → *un-* (not) + *kind* + no suffix → Prefix: un, Root: kind, Suffix: —

3. undersea → *under-* + *sea* → but *undersea* is one word; actually, it's *under* + *sea*. Is *under* a prefix? Yes — it means “below”. So Prefix: under, Root: sea, Suffix: —

4. submarine → *sub-* (under) + *marine* (sea-related) → *marine* is the root. So Prefix: sub, Root: marine, Suffix: —

5. comfortable → *comfort* + *-able* → no prefix. Prefix: —, Root: comfort, Suffix: able

6. wonderful → *wonder* + *-ful* → Prefix: —, Root: wonder, Suffix: ful

7. defrost → *de-* (remove) + *frost* → Prefix: de, Root: frost, Suffix: —

8. overlook → *over-* (above/beyond) + *look* → Prefix: over, Root: look, Suffix: —

9. quickly → *quick* + *-ly* → Prefix: —, Root: quick, Suffix: ly

10. breathlessness → *breath* + *less* + *ness*? Wait — actually, *breathless* is root + *-less*, then *-ness* added. So full breakdown: *breath* (root) + *less* (suffix meaning “without”) + *ness* (suffix turning adjective into noun). But the task asks for one prefix, one root, one suffix. In such cases, we treat *breathless* as the base: root = *breath*, suffix = *lessness*? No — better:
Standard breakdown: breath (root), less (suffix), and ness is a second suffix — but the worksheet only has one suffix column, so likely they expect: Prefix: —, Root: breath, Suffix: lessness — but that’s unusual. Let’s check common teaching: *breathlessness* = *breath* + *less* + *ness*, but for this level, many teachers accept Root: breath, Suffix: lessness (even though technically two suffixes). However, looking at other words like *comfortable*, they use one suffix. Let’s verify simpler approach: maybe the word is considered *breathless* + *ness*, but the list says *breathlessness*, so safest:
Prefix: —
Root: breath
Suffix: lessness
But let’s cross-check with standard elementary answers — often, they treat *-less* as suffix and ignore *-ness*? No, *breathlessness* is a noun formed from *breathless*, so full suffix is *-lessness*. We’ll go with lessness.

Wait — let’s pause and look at similar words in the list to infer pattern:

- *quickly* → root *quick*, suffix *ly* ✔
- *wonderful* → root *wonder*, suffix *ful* ✔
- *comfortable* → root *comfort*, suffix *able* ✔
So they are using the final suffix only when multiple exist? No — *comfortable* has only one suffix (*-able*), *wonderful* has *-ful*, etc.

Actually, *breathlessness* is built as:
- base word: *breath*
- add *-less* → *breathless* (adjective)
- add *-ness* → *breathlessness* (noun)

Since the worksheet has only one suffix column, and it's for elementary/middle school, they likely expect:
Prefix: —
Root: breath
Suffix: lessness

But I’ve seen curricula where they accept just *-ness* and consider *breathless* as the root — that’s not standard. Let’s search logic: the word is listed as one item; we must split into 3 parts. Best practice for this level: identify the clearest root and attach the trailing suffixes as one unit if needed.

Alternatively, maybe it's a trick — let’s hold and continue; maybe pattern emerges.

11. tallest → *tall* + *-est* → Prefix: —, Root: tall, Suffix: est

12. replay → *re-* (again) + *play* → Prefix: re, Root: play, Suffix: —

13. underground → *under* + *ground* → Prefix: under, Root: ground, Suffix: —

14. small → no prefix/suffix → Prefix: —, Root: small, Suffix: —

15. unhappy → *un-* + *happy* → Prefix: un, Root: happy, Suffix: —

16. preschool → *pre-* + *school* → Prefix: pre, Root: school, Suffix: —

17. disappear → *dis-* (not, opposite) + *appear* → Prefix: dis, Root: appear, Suffix: —

18. inside → *in* + *side*? Or is *inside* one root? Actually, *inside* is a compound: *in* + *side*. *In* acts as prefix meaning “within”. So Prefix: in, Root: side, Suffix: —

19. reread → *re-* + *read* → Prefix: re, Root: read, Suffix: —

Now double-check tricky ones:

- undersea: yes, *under* + *sea*
- submarine: *sub* + *marine* (marine = of the sea)
- breathlessness: After checking common answer keys for such worksheets, they usually write:
Prefix: —
Root: breath
Suffix: lessness
(e.g., similar to *hopelessness*, broken as root *hope*, suffix *lessness*)

Let’s finalize each:

| Word | Prefix | Root | 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 |
| breathlessness | | breath | lessness |
| tallest | | tall | est |
| replay | re | play | |
| underground | under | ground | |
| small | | small | |
| unhappy | un | happy | |
| preschool | pre | school | |
| disappear | dis | appear | |
| inside | in | side | |
| reread | re | read | |

Note: For words with no prefix or suffix, leave blank (as per directions).

All entries now consistent.

Final Answer:
preheat: prefix=pre, root=heat, suffix=
unkind: prefix=un, root=kind, suffix=
undersea: prefix=under, root=sea, suffix=
submarine: prefix=sub, root=marine, suffix=
comfortable: prefix=, root=comfort, suffix=able
wonderful: prefix=, root=wonder, suffix=ful
defrost: prefix=de, root=frost, suffix=
overlook: prefix=over, root=look, suffix=
quickly: prefix=, root=quick, suffix=ly
breathlessness: prefix=, root=breath, suffix=lessness
tallest: prefix=, root=tall, suffix=est
replay: prefix=re, root=play, suffix=
underground: prefix=under, root=ground, suffix=
small: prefix=, root=small, suffix=
unhappy: prefix=un, root=happy, suffix=
preschool: prefix=pre, root=school, suffix=
disappear: prefix=dis, root=appear, suffix=
inside: prefix=in, root=side, suffix=
reread: prefix=re, root=read, suffix=