何かの状態を示すために be 動詞を使います。
be 動詞は主語 [S] によって語形が is, am, are に変化します。
be 動詞の後には名詞 [O] や形容詞 [C] が続きます。
| 私 | I am | I'm | 
| あなた | you are | you're | 
| 彼 | he is | he's | 
| 彼女 | she is | she's | 
| それ | it is | it's | 
| これ | this is | this's | 
| あれ | that is | that's | 
| 私たち | we are | we're | 
| あなたたち | you are | you're | 
| 彼ら | they are | they're | 
| 彼女ら | they are | they're | 
| それら | they are | they're | 
| これら | these are | these're | 
| あれら | those are | those're | 
he, she, it, this, that をまとめて三人称単数と呼びます。