English Grammar Essentials: 7 Rules That Fix Most Errors

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: Focus on seven rules first: -s after he/she/it, the right past tense, subject-verb-object order, a/an/the, in/on/at, questions with do/does/did, and no double negatives. Practise each with a short daily exercise and keep a notebook of your own mistakes.↗ Share on X

If you only have a little time to study English grammar, focus on seven rules that cause most everyday mistakes: add -s to verbs after he, she and it; use the right past tense; put words in the order subject, verb, object; choose between a, an and the; use the correct preposition for time and place; make questions with do, does or did; and avoid double negatives. Learn these first, practise them with short daily exercises, and leave rare rules for later.

Below, each rule has a short explanation, correct and wrong examples, and a two-minute exercise. At the end you will find a one-week plan that fits into 15 minutes a day.

Why start with only seven rules?

READ ALSOPick the Right English Tense for Daily Life Easily →English Grammar Rules: 12 That Fix Most Beginner Mistakes →10 English Grammar Rules That Fix Most Beginner Mistakes →

English grammar books have hundreds of pages. Most learners never finish them. But the mistakes people make when speaking and writing are not spread evenly. A small group of rules shows up in almost every sentence you say. If you get those right, your English sounds clearer right away, even if you still make small errors elsewhere.

Think of it like learning to drive. You learn to brake, steer and use the mirrors first. Parallel parking can wait.

Rule 1: When does a verb need an -s?

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

Common mistake: "He go to school every day." → Correct: "He goes to school every day."

Verbs ending in -s, -sh, -ch, -x or -o take -es: goes, watches, fixes, washes. Verbs ending in consonant + y change to -ies: study → studies, carry → carries.

Two-minute exercise: write five sentences about a friend's daily routine using he or she. Then check every verb for the -s.

Rule 2: How do you choose the right past tense?

READ ALSO10 English Grammar Rules That Fix Most Beginner Mistakes →10 English Grammar Rules Beginners Break Most Often →12 English Grammar Rules That Fix Most Beginner Mistakes →

For most learners, two past tenses cover daily needs:

1. Past simple for finished actions at a known time: "I visited my aunt last Sunday."

2. Present perfect (have/has + past participle) for experiences or actions with no specific time: "I have visited Mexico twice."

A quick test: if the sentence has a finished time word like yesterday, last year, in 2020, two days ago, use past simple.

Irregular verbs are the hard part. Learn the most common ones first: be (was/were), have (had), do (did), go (went), get (got), make (made), say (said), see (saw), come (came), take (took), know (knew), think (thought).

Two-minute exercise: write three things you did yesterday (past simple) and three things you have done in your life (present perfect).

Rule 3: What is the basic word order?

English sentences usually follow this order: Subject + Verb + Object, then place, then time.

Common mistakes:

• "I like very much pizza." → "I like pizza very much."
• "Yesterday went I to the park." → "Yesterday I went to the park."
• "She speaks very well English." → "She speaks English very well."

The object usually stays right after the verb. Words like "very much" and "very well" go after the object, not between the verb and the object.

Two-minute exercise: write four sentences using the table above as a template, changing each column.

Rule 4: When do you use a, an and the?

These small words are called articles. Many languages do not have them, so they cause a lot of errors.

• a / an: one thing, not specific, mentioned for the first time. "I saw a dog."
• the: a specific thing both people know about. "The dog was very big."
• No article: general ideas and plural things in general. "Dogs are loyal." "I love music."

Use an before a vowel sound, not just a vowel letter: an apple, an hour (the h is silent), but a university (it sounds like "you").

A simple memory trick: jobs always need a/an ("He is an engineer"). Sports and meals usually need no article ("I have lunch at one", "We play tennis").

Two-minute exercise: describe your kitchen in five sentences. Circle every a, an and the, and ask yourself why each one is there.

Rule 5: Which preposition goes with time and place?

The three most common prepositions, in, on, at, follow a pattern from big to small.

Common mistakes:

• "I was born on 1995." → "I was born in 1995."
• "See you in Monday." → "See you on Monday."
• "She is in home." → "She is at home."

Some phrases just need to be memorised: "at night" but "in the evening"; "on the weekend" (American) and "at the weekend" (British) are both correct.

Two-minute exercise: write your weekly schedule in five sentences using in, on and at at least once each.

Rule 6: How do you make questions?

In the present simple and past simple, most questions need a helper verb: do, does or did. After the helper, the main verb goes back to its basic form.

The verb to be is different. It does not need a helper. You just swap the order: "You are tired." → "Are you tired?"

Common mistakes:

• "You like coffee?" (fine when speaking casually, but not in writing) → "Do you like coffee?"
• "Does she works here?" → "Does she work here?"
• "Where you live?" → "Where do you live?"

Two-minute exercise: write five questions you might ask a new coworker. Check that each one has do, does, did, or a form of be.

Rule 7: Why should you avoid double negatives?

In standard English, one negative word per idea is enough. Two negatives can cancel each other or look wrong in formal writing.

Simple rule: after don't, doesn't, didn't, can't, won't, use any, anything, anybody, anywhere.

Two-minute exercise: write three negative sentences about your weekend using "anything", "anybody" and "anywhere".

What does a one-week plan look like?

Fifteen minutes a day is enough to cover all seven rules in one week and review them.

After the first week, keep a small mistake notebook. Every time you notice a grammar error, yours or in your practice, write the wrong and right version side by side. Review the notebook for five minutes before each study session. Your own mistakes are the best lesson plan you can have.

Your next step

Right now, pick the rule you think you break most often. Do its two-minute exercise, then say your sentences out loud. Tomorrow, start the one-week plan on the right day. At the end of the week, write one paragraph about your week and check it against the seven rules. The number of errors you catch yourself will show you exactly which rule to practise next.

FAQ

What is the most common grammar mistake English learners make?

Forgetting the -s on verbs after he, she and it in the present simple, as in 'he go' instead of 'he goes'. It appears in almost every conversation, so fixing it helps quickly.

When do I use past simple instead of present perfect?

Use past simple when there is a finished time, like yesterday or last year. Use present perfect for life experiences with no specific time, like 'I have been to Mexico.'

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

About 15 minutes a day of focused practice is enough to cover the seven core rules in a week and keep reviewing them.

Why does 'an hour' use an and 'a university' use a?

The choice depends on the first sound, not the first letter. 'Hour' starts with a vowel sound because the h is silent; 'university' starts with a 'you' sound.