One of the most puzzling parts of English vocabulary is how to make plurals out of nouns. Here's a post to simplify that.
The English language has both regular and irregular plural forms of nouns.
1. The most common case is when you need to add -s to the noun.
For example one car and two cars.
2. Other nouns that end with s, x, ch or sh, where you add es
For example one box, two boxes
3. Some nouns that end with consonant y, where you change the y to i and add -es
For example one enemy, two enemies
1. The nouns that end with o, where you add -es
For example one potato, two potatoes
2. The nouns ending with is, where you change -is to -es
For example one crisis, two crises
3. The nouns ending with f, where you change f to v and add –ves
For example one wolf, two wolves
4. The nouns ending with fe, where you change -f to -v and add -s
For example one life, two lives
5. The nouns ending with us, where you change -us to -i
For example one fungus, two fungi
6. The nouns that contain oo, change -oo to -ee
For example one foot, two feet
7. The nouns that end with on, where you change -on with –a
For example phenomenon, phenomena
8. The nouns that don’t change. In fact it is the content that decides if it is being used in the singular or plural form.
For example sheep, offspring, series
Once you master these simple rules you will drastically improve your English Writing Skills.