English Grammar Rules: 12 That Fix Most Beginner Mistakes

Priya Sharma

Priya Sharma writes English learning guides for ESL students. Pune-based language enthusiast.

Visual representation of the voice · not a photographic portrait

Quick answer: You don't need hundreds of grammar rules to speak and write clearly. Twelve basic rules — like adding -s after he/she/it, using a/an/the correctly, and choosing between past simple and present perfect — fix most beginner mistakes. Learn them one at a time with short daily practice.↗ Share on X

You don't need to memorize a thick grammar book to speak and write English clearly. Twelve basic rules fix most of the mistakes beginners make. The biggest ones are: add -s to verbs after *he, she, it*; use a, an and the correctly; put words in the order subject + verb + object; and know when to use the past simple ("I saw") versus the present perfect ("I have seen"). Learn one rule at a time, practice it for a week, and move on.

This article explains each rule in simple words, shows right and wrong examples, and ends with a practice plan.

The 12 rules at a glance

READ ALSOPick the Right English Tense for Daily Life Easily →Daily habits to fix English grammar mistakes at work →Daily Conversation Practice Tips to Speak English Fluently Fast →

Save this table. It is your quick checklist.

Now let's look at each one.

How do verbs change after he, she and it?

Rule 1: Add -s in the present simple

In the present simple (the tense for habits and facts), add -s or -es to the verb when the subject is *he, she, it* or one person or thing.

• I work. You work. We work. They work.
• He works. She works. It works. My brother works.

Spelling tips:

• Verbs ending in *-ch, -sh, -s, -x, -o* add -es: watch → watches, go → goes.
• Verbs ending in consonant + *y* change to -ies: study → studies.
• *Have* becomes has: She has a car.

Rule 2: Use do and does for questions and negatives

Most English questions in the present simple need do or does before the subject.

• Do you like coffee?
• Does he live here?

Notice: after *does*, the main verb loses its -s. "Does he live," not "Does he lives."

Negatives work the same way: *I don't eat meat. She doesn't eat meat.*

Why does English allow only one negative?

READ ALSOHow to Remember Irregular Verbs for Everyday Conversation →How to Use “Have” and “Has” in English Questions Correctly →Easy Rules to Use A and An Without Mistakes →

Rule 3: Avoid double negatives

In many languages, two negative words make a stronger "no." In standard English, use only one.

• Wrong: I don't have nothing.
• Right: I don't have anything. / I have nothing.

Pairs to remember: *don't … anything*, *don't … anyone*, *never … anything*.

What order do English words go in?

Rule 4: Subject + verb + object

English word order is strict. The basic pattern is who + does what + to what.

• Maria (subject) reads (verb) books (object).

Words that describe *how much* or *how often* have their own places:

• "Very much" goes after the object: I like pizza very much.
• Words like *always, usually, often, never* go before the main verb: She always arrives early.
• But they go after the verb *to be*: He is always late.

Rule 7: Adjectives come before nouns

Adjectives (words that describe) usually go before the noun, and they never take -s.

• a red car → two red cars (not "reds cars")
• a big house, an old friend

When do you use a, an and the?

Rule 5: A or an depends on sound

Use an before a vowel sound and a before a consonant sound. Listen to the sound, not the letter.

• an apple, an egg, an hour (the "h" is silent)
• a car, a dog, a university (sounds like "you")

Rule 6: When to use "the"

Use the when both people know which thing you mean.

• I bought a phone. The phone is black. (Now we know which phone.)
• Please close the door. (The door in this room.)

Don't use *the* when talking about things in general:

• Dogs are friendly. (All dogs, in general)
• I love music. (Music in general)

Also no *the* before most names of people, cities and countries: *Paris, Japan, John*. A few countries are exceptions: *the United States, the United Kingdom*.

Can you count it or not?

Rule 8: Countable and uncountable nouns

Countable nouns can be counted: one apple, two apples. Uncountable nouns can't be counted one by one and have no plural.

Common beginner mistakes with uncountable nouns:

• Wrong: *informations, advices, furnitures, homeworks*
• Right: *information, advice, furniture, homework*

If you need to count them, use a helper word: a piece of advice, a glass of water.

*A lot of* works with both types: a lot of books, a lot of money.

Which preposition goes with time: in, on or at?

Rule 9: The in-on-at triangle

Think of it as going from big to small.

Americans say *on the weekend*. British speakers say *at the weekend*. Both are correct.

Present simple or present continuous?

Rule 10: Habits vs. right now

• Present simple = habits, routines, facts. *I work in a bank. Water boils at 100°C.*
• Present continuous (am/is/are + verb-ing) = happening now or around now. *I am working from home this week.*

The most common mistake is forgetting the -ing or the *am/is/are*:

• Wrong: I am work. / I working.
• Right: I am working.

Some verbs are rarely used with -ing, because they describe states, not actions: *know, like, want, need, believe*. Say "I know," not "I am knowing."

Past simple or present perfect?

Rule 11: Finished time vs. connection to now

This rule confuses many learners, so keep it simple:

• Past simple = a finished action at a finished time. Often used with *yesterday, last week, in 2019, ago*.

- *I saw that movie last week.*

• Present perfect (have/has + past participle) = the time is not finished or not said, or the result matters now.

- *I have seen that movie.* (At some point in my life.)

- *She has lived here since 2018.* (She still lives here.)

Key words:

• since + a starting point: since Monday, since 2018
• for + a length of time: for three days, for ten years

Wrong: *I have seen him yesterday.* → Right: *I saw him yesterday.*

How do you stop mixing it's and its?

Rule 12: The apostrophe test

• It's = *it is* or *it has*. *It's raining. It's been a long day.*
• Its = belonging to it. *The company changed its logo.*

Test: replace the word with "it is." If the sentence still makes sense, write it's. If not, write its.

Your practice plan: 15 minutes a day

Grammar sticks when you use it, not just read it. Try this plan:

1. Pick one rule per week. Start with Rule 1 and go in order.

2. Day 1: Read the rule and write 5 of your own sentences using it.

3. Days 2 to 4: Every day, write 3 sentences about your real life using the rule. Example for Rule 1: "My sister works in a school."

4. Day 5: Read a short news story or a page of a simple book and find 5 examples of the rule. Underline them.

5. Day 6: Say 5 sentences out loud and record them on your phone. Listen for the mistake.

6. Day 7: Review. Go back to the table at the top and cover the "Right" column. Can you fix each "Wrong" sentence?

Your next step right now

Look at the table of 12 rules and choose the one you get wrong most often. Write three true sentences about your day using that rule — for example, "My boss doesn't work on Fridays." Check them against the examples in this article. Tomorrow, write three more. After one week, move to the next rule on your list.

FAQ

What is the most important English grammar rule for beginners?

Subject-verb agreement in the present simple: add -s or -es to the verb after he, she or it. "She works," not "She work."

When do I use "a" and when do I use "an"?

It depends on the first sound, not the first letter. Use "an" before a vowel sound (an hour, an apple) and "a" before a consonant sound (a university, a car).

What is the difference between "it's" and "its"?

"It's" means "it is" or "it has." "Its" shows that something belongs to it, like "The dog wagged its tail."

How long does it take to learn basic English grammar?

It depends on your practice time. Focusing on one rule each week with 15 minutes of daily practice is a realistic way to build solid habits.