The verb be is used in the following patterns:
1. with a noun:
My mother is a teacher.
Bill Clinton was the president of the US.
2. with an adjective:
This soup is very tasty.
The children were good.
2.1 with the -ing form to make the continuous aspect
We were walking down the street.
Everything was wet. It had been raining for hours.
2.2 with the -ed form to make the passive voice
The house was built in 1890.
The street is called Montagu Street.
This car was made in Japan.
3. with a prepositional phrase:
John and his wife are from Manchester.
The flowers are on the table.