Some spelling rules:

A common spelling rule: "i before e, except after c."

Examples: believe and friends (i before e)
Examples: receive and deceit (except after c)

Two exceptions to this common spelling rule:

1) When the letters "e and i" make the sound "ay" (examples: neighbor, weigh),
put the "e" first.
2) When the letters (i,e) are preceded by the letter "c" and followed by "n" (the letters-CIEN all together), put the "i" before the "e." Two examples: ancient and science.

Other exceptions to the "i before e except after c" rule: either, foreign, height, leisure, protein, and weird.

For nouns ending with s, z, x, ch, sh, form the plural by adding es.

When in doubt, Google.

Spelling Irregular Plural Nouns

Irregular plural nouns are nouns that do not become plural by adding -s or -es, as most nouns in the English language do. What follows are Bible quotes with irregular plural nouns underlined.
Can you think of the singular forms of the underlined words below?

"But to all who did receive him, who believed in his name, he gave the right to become children of God, who were born, not of blood nor of the will of the flesh nor of the will of man, but of God." John 1:12-13.

"For you have delivered my soul from death, my eyes from tears, my feet from stumbling;" Psalm 116:8.

"The men were amazed and asked, "What kind of man is this? Even the winds and the waves obey him!" Matthew 8:27.

"This is how we know what love is: Jesus Christ laid down his life for us. And we ought to lay down our lives for our brothers and sisters." 1 John 3:16.

"Husbands, love your wives, and do not be harsh with them." Colossians 3:19.

"They will be like a tree planted by the water that sends out its roots by the stream. It does not fear when heat comes; its leaves are always green." Jeremiah 17:8.

Some nouns are spelled the same way whether they are singular or plural.

"Once again, the kingdom of heaven is like a net that was let down into the lake and caught all kinds of fish." Matthew 13:47.

"But he was pierced for our transgressions, he was crushed for our iniquities, and by his wounds, we are healed. We all, like sheep, have gone astray, each of us has turned to our own way and the Lord has laid on him the iniquity of us all." Isaiah 53:5-7.

"As the deer pants for streams of water, so my soul pants for you, my God." Psalm 42.

"When they had crucified him, they divided up his clothes by casting lots." Matthew 27:35.

Words ending in -o are usually made plural by adding -es.

For musical terms ending in an o add s.

Nouns ending in consonants and o (some add only "s" and others add "es"): logo/logos, taco/tacos, casino/casinos, ego/egos, tomato/tomatoes, potato/potatoes, echo/echoes, veto/vetoes.

Very common errors are made with potato and tomato (potatoes, tomatoes).
In 1992, Vice President Dan Quayle misspelled "potato" while visiting a sixth-grade class (he put an -e at the end). Maybe, he was thinking of the rule to make potato plural by adding -es.

"Hero" is singular and "heroes" is the plural spelling.

"Woe to those who are heroes at drinking wine and champions at mixing drinks," Isaiah 5:22.

Making words plural that end in "y":

Some nouns that end in -f or -fe are changed to -ves in the plural (loaf/loaves leaf/leaves knife/knives life/lives wife/wives)
Some nouns do not change at all (fish/fish sheep/sheep deer/deer offspring/offspring).

Check out the following common spelling error:

When touring the capital, why not visit the capitol? Capital and capitol are terms that are often confused, mainly because they refer to things that are in some ways related.
The term for a town or city that serves as a seat of government is spelled capital.
The term for the building in which a legislative assembly meets is spelled capitol.

Be careful with words ending with the seed sound.

Most words that end with the seed sound are spelled cede at the end: intercede, precede, recede, secede, ect.
There are three words ending with the seed sound that are spelled ceed at the end: exceed, proceed, and succeed.
There is only one word ending with the seed sound that is spelled sede at the end: supersede.

Suffixes: able, ible

able is more common than ible
Examples: workable, dependable, detectable
The last letter or sound in the last syllable determines the suffix.

The suffix able follows g, i, and the hard c sound ("k" sound).
Examples: navigable (/g/), amiable (/i/), irrevocable (/k/).

The suffix ible follows s, st, some d sounds, and the soft c sound (/s/) for example the soft c sound (/s/) in discernible.
Other examples: plausible (/s/), digestible (/st/), edible (/d/), forcible (/s/)
The suffix ible is used after double consonants.
For example: infallible (double-ll).

Words ending in "y."

For nouns ending in a vowel and y, form the plural by adding s.

For nouns ending in a consonant and y, form the plural by changing the y to ie and adding s.

Words ending in "f" or "fe."

One way to form irregular plurals ending in "f" or "fe": life/lives, knife/knives, wolf/wolves, leaf/leaves, scarf/scarves.

"Beware of false prophets, who come to you in sheep's clothing but inwardly are ravenous wolves." Mathew 7:15.

"There are those whose teeth are swords, whose fangs are knives, to devour the poor from off the earth, the needy from among mankind. Proverbs 30:14.

Two ways to form these irregular plurals ending in "f" or "fe": dwarf= dwarfs or dwarves, hoof= hoofs or hooves, wharf= wharfs or wharves.

"I will praise the name of God with a song; I will magnify him with thanksgiving. This will please the Lord more than an ox or a bull with horns and hoofs. Psalm 30-31.

The following words are often misspelled:

Common ESL Errors (Nouns)

Try to correct these common errors:

How many childrens do you have?
I have five girl.
Every girls speaks Spanish and English.
I have dog.
You must have the patience and the hope.
I was born in mexico city.

CORRECTIONS:

How many children do you have?
I have five girls.
Every girl speaks Spanish and English.
I have a dog.
You must have patience and hope.
I was born in Mexico City.

Here are some problematic non-count nouns:
homework, information, machinery.

Try to correct these common errors:

We have many homeworks.
Thank you for the advices.

CORRECTIONS:

We have a lot of homework.
Thank you for the advice.

Common ESL Errors (Pronouns)

Try to correct these common errors:

My favorite city is San Juan Capistrano. Is a very special place to me.
Do you know my uncle? I think that she is your neighbor.
Cars are important. People need it in today's world.
My brother he lives in Mexico.
A computer is something that all students need it.
Everyone were very happy.

CORRECTIONS:

My favorite city is San Juan Capistrano. It is a very special place for me.
Do you know my uncle? I think he is your neighbor.
Cars are important. People need them in today's world.
My brother lives in Mexico.
A computer is something that all students need.
Everyone was very happy.

Common ESL Errors (Verbs)

Try to correct these common errors:

We have hungry now.
The teacher drive a Toyota.
My sister no lives in Mexico now.
Why you need English classes.
She can't go now because she cooks the dinner.
How long do you live here.
We came to the United States. Later, we have three children.
The lunch was great! We enjoyed very much.
I believe that everyone should to learn a second language.

CORRECTIONS:

We are hungry now.
The teacher drives a Toyota.
My sister does not live in Mexico now.
Why do you need English classes?
She can't go now because she is cooking dinner.
How long have you lived here?
We came to the United States. Later, we had three children.
The lunch was great! We enjoyed it very much.
I believe that everyone should learn a second language.

Try to correct these negative form errors:

I no speak English well.
She is not like this food.
The fish doesn't smells good.

CORRECTIONS:

I do not speak English well.
She does not like this food.
The fish doesn't smell good.

Common ESL Errors (Adjectives)

Try to correct these common errors:

China is a country very big.
These books are very cheaps.
China is more big than Japan.
In the winter, the weather here is very rain.

CORRECTIONS:

China is a very big country.
These books are very cheap.
China is bigger than Japan.
In the winter, the weather here is very rainy.

Common ESL Errors (Adverbs)

Try to correct these common errors:

She plays the violin very beautiful.
I like very much this food.
The teacher explained the lesson detailly.

CORRECTIONS:

She plays the violin very beautifully.
I like this food very much.
The teacher explained the lesson in detail.

Common ESL Errors (Conjunctions)

Try to correct these common errors:

The test was difficult, I did not do well.
The test was difficult so I did not do well.
Although I watched the movie, but I did not enjoy it.
Our flight to Boston was delayed. Because the weather was really bad.

CORRECTIONS:

The test was difficult. I did not do well on it.
The test was difficult for me, so I did not do well.
Although I watched the movie, I did not enjoy it.
Our flight to Boston was delayed because the weather was really bad.

Common ESL Errors (Prepositions)

Try to correct these common errors:

I have a appointment at monday.
He work on his office, in Main Street.
I am waiting the bus.
How can we avoid for any problems?
The car is full from gasoline right now.

CORRECTIONS:

I have an appointment on Monday.
He works in his office on Main Street.
I am waiting for the bus.
How can we avoid any problems?
The car is full of gasoline right now.

Common ESL Errors (Present Perfect Tense)

Try to correct these common errors:

I lived here my whole life.
Sara has already did all the homework.
We don't have eaten at the restaurant yet.
I borrowed the book last week. I doesn't have returned the book yet.

CORRECTIONS:

I've lived here my whole life.
Sara has already done all the homework.
We haven't eaten at the restaurant yet.
I borrowed the book last week. I haven't returned it yet.