English Grammar in 15 Minutes a Day: The 8 Rules That Matter

Priya Sharma

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

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Quick answer: Focus on eight rules: the -s for he/she/it, present simple vs continuous, past simple, present perfect, a/an/the, in/on/at for time, question word order, and countable vs uncountable nouns. Study one rule a day for 15 minutes and use it out loud.↗ Share on X

If you have limited time, do not try to learn every English grammar rule. Learn the eight rules that cause most everyday mistakes: the -s for he, she and it; present simple vs present continuous; past simple; present perfect; a, an and the; in, on and at for time; question word order; and countable vs uncountable nouns. Study one rule a day for 15 minutes, and use it out loud in your own sentences. In two weeks, you will fix the mistakes people notice most.

Which grammar rules give you the most for your time?

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English has hundreds of grammar points. But in daily speaking and writing, a small group of rules shows up again and again. If you get these right, your English sounds much clearer, even if you still make small mistakes elsewhere.

Here is the list, in the order we suggest you learn them:

Now let's look at each rule in simple steps.

Rule 1: When do you add -s to a verb?

In the present simple, add -s 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.

Small spelling changes:

• Verbs ending in -ch, -sh, -ss, -x, -o add -es: watches, washes, goes, does.
• Consonant + y becomes -ies: study → studies. But vowel + y just adds -s: play → plays.
• have becomes has: She has two kids.

In negatives and questions, the -s moves to does, and the main verb goes back to its base form:

• She doesn't like coffee. (Not: She doesn't likes coffee.)
• Does he live here? (Not: Does he lives here?)

Rule 2: Present simple or present continuous — which one?

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This is one of the most common mix-ups.

How to form the present continuous: am / is / are + verb-ing.

• I am working. He is working. They are working.

Watch out: some verbs are almost never used in the continuous form. They describe states, not actions. Common ones: know, like, love, want, need, believe, understand, own.

• I know the answer. (Not: I'm knowing the answer.)
• She wants a new job. (Not: She's wanting a new job.)

Rule 3: How do you use the past simple?

Use the past simple for actions that finished at a specific time in the past: yesterday, last week, in 2019, two hours ago.

• Regular verbs add -ed: work → worked, play → played, study → studied.
• Irregular verbs change form. You have to learn them. Start with the most common: go → went, have → had, do → did, see → saw, make → made, get → got, come → came, take → took, say → said, buy → bought.

In negatives and questions, use did + base verb:

• I didn't go. (Not: I didn't went.)
• Did you see it? (Not: Did you saw it?)

Rule 4: When do you use the present perfect?

The present perfect is have / has + past participle: I have seen, she has finished.

Use it when the time is not finished or not important, and the action connects to now:

• Life experience: I've been to Mexico. (When? Not important.)
• Something that started in the past and continues: She has lived here for five years. (She still lives here.)
• A recent action with a result now: I've lost my keys. (They are still missing.)

The simple test: Is there a finished time word? If yes, use the past simple.

• I saw that movie last night. (Finished time → past simple.)
• I've seen that movie. (No finished time → present perfect.)

Words that often go with the present perfect: ever, never, already, yet, just, for, since.

• for + a length of time: for three years.
• since + a starting point: since 2021, since Monday.

Rule 5: When do you use a, an and the?

Use a / an for one thing that is new or not specific.

• a before a consonant sound: a car, a university (sounds like "you").
• an before a vowel sound: an apple, an hour (the "h" is silent).

Use the when both people know which one you mean.

• I bought a phone. The phone is black. (First time: a. Second time: the.)
• Can you close the door? (There is only one door we both know about.)

Use no article for general ideas with plural or uncountable nouns:

• Dogs are friendly. (Dogs in general.)
• I like music. (Music in general.)

Rule 6: in, on or at — which one for time?

Think of it as a pyramid: big times at the top, small times at the bottom.

Common exceptions:

• at night (not "in the night" for general use)
• on the weekend (American) / at the weekend (British)
• No preposition with this, next, last, every: I'll call you next Monday. (Not: on next Monday.)

Rule 7: What is the right word order in a question?

Most questions follow this pattern:

(Question word) + helper verb + subject + main verb + rest

• Where do you live?
• What did she say?
• How long have they worked here?
• Why is he laughing?

The most common mistake is keeping normal sentence order:

• Wrong: Where you live?
• Right: Where do you live?

When the question word is the subject, you do not need do/does/did:

• Who called you? (Not: Who did call you?)
• What happened? (Not: What did happen?)

Rule 8: Countable or uncountable — why does it matter?

Countable nouns can be counted: one apple, two apples. Uncountable nouns cannot: water, money, advice, information, furniture, news.

This changes the words you use with them:

a lot of and some work with both: a lot of people, a lot of water.

Watch out for these. They are uncountable in English, even if they are countable in your language:

• advice → a piece of advice (not "an advice")
• information → some information (not "informations")
• homework, equipment, luggage, news

What are the most common mistakes, and how do you fix them?

Save this table on your phone and read it before an email or meeting.

A two-week plan: 15 minutes a day

1. Days 1–8: Study one rule per day, in the order above. Spend 5 minutes reading the rule, 5 minutes writing five of your own sentences, and 5 minutes saying them out loud.

2. Days 9–12: Review two rules per day. Write a short paragraph about your day that uses both.

3. Day 13: Write 10 sentences about your last weekend. Check each one against the mistakes table.

4. Day 14: Record yourself talking for two minutes about your job or studies. Listen back and write down every grammar mistake you hear. Those are the rules to review next week.

Short daily practice beats one long weekly session, because repetition makes a rule automatic.

Your next step

Start with Rule 1 today. Write five sentences about someone you know, using he or she and the present simple: *My sister works…, She likes…, She doesn't…* Say them out loud twice. Then save the mistakes table on your phone and read it once before bed. Tomorrow, move to Rule 2.

FAQ

Which English grammar rules should I learn first?

Start with the -s for he, she and it, then present simple vs present continuous, past simple, present perfect, articles, in/on/at for time, question word order, and countable vs uncountable nouns.

How much time do I need each day to improve my grammar?

About 15 minutes a day is enough to make steady progress if you practice every day and say your example sentences out loud.

What is the difference between past simple and present perfect?

Use past simple when there is a finished time, like yesterday or last year. Use present perfect when the time is not finished or not important, like life experiences or something that continues to now.