BE is the most important verb in English — a verb is a word that shows an action (like eat or go) or a state (a condition, like being happy or being in a place). BE has three forms in the present: I am, he/she/it is, and you/we/they are. Use BE to say who someone is, where someone is, and how someone feels: 'She is my teacher.' 'We are at home.' 'I am happy.'
2. Detailed explanation
Start from zero. An English sentence needs a verb. A verb is a word that shows an action (eat, go, run) or a state (a condition — being happy, being a teacher, being in a place). The person or thing a sentence talks about is called the subject — the subject is simply who or what the sentence is about. This lesson teaches one verb: BE. BE connects the subject to a description, a job, a place, or a feeling. In English you can never just leave it out: 'She happy' is wrong; 'She is happy' is right.
BE is special because it has three shapes in the present: am, is, and are. The subject chooses the shape. With I, use am: 'I am.' With he, she, it — and with one person or one thing, like 'the dog' or 'my mother' — use is: 'She is,' 'The dog is.' One person or one thing is called singular (singular means 'only one'). With you, we, they — and with two or more people or things, like 'the dogs' or 'my parents' — use are: 'They are.' More than one is called plural (plural simply means 'more than one'). So the whole table is: I am — he/she/it is — you/we/they are.
Let's take three example sentences apart, word by word. 'She is happy': She (the person — a woman) + is (the BE form for she) + happy (her feeling — how she is). 'They are at home': They (a group of people) + are (the BE form for they) + at home (the place — where they are). 'I am a teacher': I (me, the speaker) + am (the BE form for I) + a teacher (my job — what I am). Notice the little word 'a' before a job: English says 'a teacher,' 'a doctor,' 'a student.'
Negatives are easy: put 'not' after am, is, or are — 'He is not late.' Questions are easy too: move BE to the front — 'He is late' becomes 'Is he late?' Never use 'do' or 'does' with BE; BE does the work alone. Answer yes/no questions with a short answer — just the person-word plus BE: 'Are you tired?' — 'Yes, I am.' / 'No, I'm not.' When speaking, Americans almost always use the short joined forms, called contractions: I am → I'm, she is → she's, they are → they're. They mean the same thing, only faster. You will use BE for names, jobs, feelings, weather, origin, and places — 'I am Alex,' 'She is a nurse,' 'I am hungry,' 'It is cold,' 'The keys are on the table.'
Remember this first: memorize only three things before anything else. One: the table — I am, he/she/it is, you/we/they are. Two: age uses BE, never 'have' — 'I am 25.' Three: in English you can never leave BE out — 'She is happy,' never 'She happy.' If you know these three things, you already understand this whole lesson.
3. Formula / structure
negative:
subject + am/is/are + not → I am not tired. / He is not (isn't) late. / We are not (aren't) ready.
positive:
subject + am/is/are + noun/adjective/place → I am a teacher. / She is happy. / They are at school.
question:
Am/Is/Are + subject + …? → Are you a student? / Is it cold today? / Where are my keys?
short answer:
Yes, + subject + am/is/are. / No, + subject + am/is/are + not. → Yes, I am. / No, she isn't.
Step by step — how to build a sentence:
Positive: 1) Start with the subject (She). 2) Choose the BE form for that subject (She → is). 3) Add the description, job, or place (happy). Result: 'She is happy.' Negative: 1) Subject (He). 2) BE form (He → is). 3) Add 'not' right after BE. 4) Add the rest. Result: 'He is not happy.' Question: 1) Start from the positive sentence (You are ready). 2) Move the BE verb to the very front. Result: 'Are you ready?'
4. When to use it
Identity and names: 'I am Alex.' / 'This is my brother.'
Jobs and roles: 'She is a nurse.' / 'They are engineers.'
Nationality and origin: 'We are from Brazil.' / 'He is American.'
Age: 'My daughter is six.' / 'How old are you?'
Feelings and states: 'I am hungry.' / 'She is tired.' / 'They are happy.'
Location: 'The bank is on Main Street.' / 'We are at home.'
Descriptions and the weather: 'The test is easy.' / 'It is sunny today.'
5. When NOT to use it
Don't use BE with an action verb in the present simple: ✗ 'I am go to school' → ✓ 'I go to school.' (BE returns when the action is happening now: 'I am going.')
Don't add do/does with BE: ✗ 'Do you are happy?' → ✓ 'Are you happy?'
Don't drop BE: ✗ 'She happy' → ✓ 'She is happy.' English sentences always need the verb.
Don't use am/is/are for age with 'have': ✗ 'I have 20 years' → ✓ 'I am 20 (years old).'
6. Positive examples
I am a student at a language school.
She is my best friend.
He is a taxi driver in New York.
It is a beautiful day.
We are ready for the trip.
They are from Canada.
You are a good cook.
The coffee is hot.
The museum is next to the park.
My parents are both doctors.
This soup is delicious.
Your homework is on the desk.
7. Negative examples
I am not tired.
He isn't at work today.
She is not a doctor — she's a nurse.
We aren't late.
They are not from Spain.
It isn't cold outside.
8. Questions
Are you from the United States?
Is she your sister?
Where is the bathroom?
How old is your son?
What is your phone number?
Are they at home now?
9. Short answers
Yes, I am. / No, I'm not.
Yes, he is. / No, he isn't.
Yes, it is. / No, it isn't.
Yes, we are. / No, we aren't.
Yes, they are. / No, they aren't.
10. Common mistakes
✗ I is a student✓ I am a student.The word 'I' always goes with 'am.' Each person-word has its own BE form: I am, she is, they are — 'I is' mixes two of them.
✗ She are happy✓ She is happy.'She' means one woman — one person always goes with 'is.' 'Are' is for 'you,' 'we,' 'they,' and for more than one person.
✗ They is friends✓ They are friends.'They' means more than one person, so it needs 'are,' the BE form for groups.
✗ He not is a teacher✓ He is not a teacher.In a 'no' sentence, 'not' comes after the BE verb — always in this order: is + not.
✗ You are happy? (written as a question)✓ Are you happy?To ask a question, move the BE verb to the very front of the sentence. People sometimes just raise their voice when speaking, but in writing and careful English, BE must come first.
✗ I have 25 years✓ I am 25.Some languages use the word for 'have' to talk about age. English never does — age always uses the BE verb: 'She is ten,' 'They are forty.'
✗ My sister she is a doctor✓ My sister is a doctor.Do not say the person twice. 'My sister' already tells us who the sentence is about, so the extra 'she' must go.
11. American English notes
🇺🇸 American English
Americans contract BE almost all the time in speech and informal writing: I'm, you're, he's, she's, it's, we're, they're — and 'there's' for 'there is.' Saying the full forms ('I am happy') is correct but can sound very formal or emphatic. In questions, Americans usually answer with the short answer, not a full sentence: 'Are you ready?' — 'Yes, I am' (never 'Yes, I'm' — the contraction cannot end a short answer). Two classic American patterns: 'How are you?' — 'I'm good, thanks' and introductions: 'Hi, I'm Mike. — Nice to meet you. I'm Sarah.' Note that Americans say 'I am 30 years old' — age always uses BE, and in quick speech the words often shrink further: 'Whaddaya…' no — for BE itself, simply learn the seven contractions and you will sound natural.
12. Similar grammar — comparison
Compare
BE is different from action verbs like go, work, and eat. Action verbs need do/does for negatives and questions ('She doesn't work,' 'Does he eat meat?'), but BE never uses do/does: negatives add not ('She is not…'), and questions move BE first ('Is she…?'). A second difference: action verbs never change with I/you/we/they, but BE changes for every group (am/is/are). Never mix the two systems in one sentence: ✗ 'Does she is a doctor?' ✗ 'I am work here.' One verb, one system.
13. Natural spoken English
'Hi, I'm Jake. What's your name?'
'I'm not sure. Let me check.'
'Are you okay? You look tired.'
'It's fine, no problem.'
'We're almost there — five more minutes.'
'She's not home right now.'
14. Real-life examples
On a form: 'I am a US citizen.' / 'Marital status: I am married.'
At a hotel: 'I'm here for two nights. My name is Carter.'
Small talk: 'So, are you from around here?'
On the phone: 'Hello, is this the pharmacy? — Yes, it is.'
Signs and labels: 'This seat is taken.' / 'Bag is not allowed.' → natural sign English: 'No bags allowed,' but in full sentences: 'This area is for staff only.'
At the doctor: 'I'm allergic to peanuts.' / 'It hurts here.'
15. Mini dialogue
AHi! I'm Emma. What's your name?
BI'm Diego. Nice to meet you, Emma.
ANice to meet you too. Are you from Mexico?
BYes, I am. I'm from Mexico City. And you?
AI'm from Chicago. I'm a teacher here.
BOh, that's great. Is this your first class?
ANo, it isn't. It's my third year.
16. Summary
BE has three present forms — am (I), is (he/she/it), are (you/we/they) — and it makes negatives with not and questions by moving to the front, with no do or does.
17. Practice exercises
Warm up with the first questions, then take the full quiz — every answer has a detailed explanation (parts 19–20 of this lesson: answer key + explanations live inside the quiz feedback).
18. The full quiz
50 questions, mixed formats, in difficulty order: easy → medium → intermediate → challenging → advanced.