ser

You all are sisters.

'Sois' is the second-person plural form of 'ser' in Spain, used here to indicate a family relationship.

He is a good doctor.

'Es' is used to convey the professional identity of a person, in this sentence specifies that he is a doctor.

I am a Spanish teacher.

'Soy' is used to indicate one's occupation in the present tense.

She is tall.

'Es' is utilized here to describe a characteristic of the subject.

They are honest men.

'Son' is the third-person plural form of 'ser', describing a characteristic and specifying who or what the subject is.

You are very fast.

'Eres' is the second person singular blend of 'to be', which underlines a personal trait in this example.

That is important.

We use 'Es' here to signify a single item’s characteristic, using the third-person singular form of 'ser'.

I am brave!

This sentence uses 'soy', the first-person present tense of the verb 'ser' which is used to describe inherent qualities such as being brave.

You are very smart.

'Es' is the third-person singular form of 'ser', used here to compliment someone on their intelligence.

We are friends.

'Somos' is the first-person plural form of 'ser', used here to describe a perpetual or current solid state which in this case is to be friends.