Grade 4 English noun worksheet with pluralization exercises and word sorting activity.

Let's solve the worksheet step by step.

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Part 1: Write the plural (if needed) of these words

We need to find the correct plural form for each word. Some words have irregular plurals, and some remain the same in singular and plural forms.

1. thesis → theses
*Explanation:* Words ending in "-is" often change to "-es" in plural (e.g., thesis → theses).

2. cirrus → cirri
*Explanation:* "Cirrus" is a Latin word; its plural is "cirri".

3. fish → fish or fishes
*Explanation:* "Fish" is an irregular noun. It can be used as both singular and plural. However, when referring to different types of fish, we use "fishes" (e.g., many fishes in the sea). But generally, "fish" is acceptable for plural too. For this level, fish is acceptable.

4. step-uncle → step-uncles
*Explanation:* Compound nouns like "step-uncle" form plurals by adding "-s" to the main noun ("uncle").

5. observatory → observatories
*Explanation:* Add "-ies" to words ending in "-ary" (like library → libraries).

6. loaf → loaves
*Explanation:* Words ending in "-f" often change to "-ves" in plural (e.g., leaf → leaves, knife → knives). So, "loaf" becomes "loaves".

7. syllabus → syllabi or syllabuses
*Explanation:* "Syllabus" is a Latin word. Its traditional plural is syllabi, but syllabuses is also acceptable in modern English. Both are correct, but syllabi is more formal.

8. spotlight → spotlights
*Explanation:* Regular plural — just add "-s".

9. agenda → agendas
*Explanation:* Though "agenda" comes from Latin, the plural "agendas" is widely accepted in modern English. The original Latin plural "agendae" is rare.

10. most → most
*Explanation:* "Most" is not a countable noun. It can function as a pronoun or determiner and does not have a plural form. So, it remains most.

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Part 2: Sort the following words into Singular or Plural boxes

List of words:
- tax
- poppies
- wharf
- churches
- atlases
- leaves
- faxes
- motto
- kiss
- stitch
- emphases
- flushes
- life
- arch
- babies
- brushes

Now, identify which are singular and which are plural:

#### ✔ Singular Words:
- tax
- wharf
- motto
- kiss
- stitch
- arch
- life

These are all in their singular form.

#### ✔ Plural Words:
- poppies
- churches
- atlases
- leaves
- faxes
- emphases
- flushes
- babies
- brushes

These all end in "-s", "-es", or have irregular plural forms.

> Note: "atlases" is the plural of "atlas", "emphases" is plural of "emphasis", etc.

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✔ Final Answers:

#### Part 1: Plural Forms
1. thesis → theses
2. cirrus → cirri
3. fish → fish (or fishes)
4. step-uncle → step-uncles
5. observatory → observatories
6. loaf → loaves
7. syllabus → syllabi or syllabuses
8. spotlight → spotlights
9. agenda → agendas
10. most → most

#### Part 2: Sorting

Singular:
- tax
- wharf
- motto
- kiss
- stitch
- arch
- life

Plural:
- poppies
- churches
- atlases
- leaves
- faxes
- emphases
- flushes
- babies
- brushes

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✔ Summary

This worksheet helps students understand:
- Regular and irregular plural forms.
- How compound nouns form plurals.
- How to recognize singular vs. plural nouns based on endings and context.

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