All sentences with be have a complement. The complement tells you more about the subject. There are three kinds of complement.
Subject Petrol is Verb Complement not green.
an energy source. from oil.
Unit 2
15. Sentences with be + adjective pp22–23 Subject Verb am
I He
She They
is are bored. friendly. polite.
16. Formation of adjectives pp22–23 There are some common endings for adjectives.
terr
comfort wonder
ible able ful
care
danger eas
less ous y
However, there are many adjectives which do not have a particular ending. Examples: hard, difficult, polite, smart, dark, bright, safe, small, cheap, good, bad
17. Negatives with be pp22–23 Subject Verb not am
I He
She They
is are not Complement/Adverbial an engineer. polite. in a factory.
interest skill
import
ing ed
ant Complement adjective noun phrase preposition + noun