Be: am / is / are, was / were

Be has three present forms: am, is and are. The subject decides which one you use. In speech, native speakers almost always use the short forms.

A singular noun takes is (My phone is…), a plural noun takes are (These shoes are…). There is no “amn't” — the negative of I am is I'm not.

Be links the subject to information about it: what it is, what it is like, where it is, how old it is, where it comes from.

• My sister is a nurse.

  be + noun

• The coffee is too sweet.

  be + adjective

• Your keys are on the table.

  be + place

• I'm twenty-three.

  age uses be, not have

• We're from Da Nang.

• It's cold today. It's half past seven.

  weather and time: the subject is it

💡Many languages can say “She tall” or “I tired” with no verb. English always needs be before an adjective: She is tall, I'm tired.

To make a question, put am / is / are before the subject. A question word (where, how old, what…) goes first.

• Are you hungry?

• Is your brother at home?

• Where is the bus stop?

• How old are your kids?

Short answers: Yes, I am. / No, I'm not. — Yes, it is. / No, it isn't. A “yes” short answer is never contracted: say “Yes, I am”, not “Yes, I'm”.

• I was at the gym last night.

• The tickets weren't expensive.

• Were you nervous before the interview?

• Where was she yesterday? — She was in Hanoi.

• ✗She very friendly.

  ✓She is very friendly.

  You still need be before an adjective.

• ✗I have 25 years old.

  ✓I'm 25 (years old).

  Age uses be.

• ✗My parents is teachers.

  ✓My parents are teachers.

  Plural subject → are.

• ✗Yes, I'm.

  ✓Yes, I am.

  Positive short answers are not contracted.

• ✗I am agree with you.

  ✓I agree with you.

  agree is a verb; it doesn't need be.