- Forma
Partes principales: «be,» «was,» «been»
Gerundio/participio de presente: «being»
Tiempo presente:
Afirmativa: I am / I’m; you are / you’re; he is / he’s // she is / she’s // it is / it’s; we are / we’re; you are / you’re; they are / they’re.
Negativa: I am not / I’m not; you are not / you’re not; he is not / he’s not // she is not / she’s not // it is not / it’s not; we are not / we’re not; you are not / you’re not; they are not / they’re not.
Interrogativa: am I? are you? is he? is she? is it? are we? are you? are they?
Contracciones negativas alternativas: you aren’t; he isn’t etc.
Interrogativa negativa: am I not / aren’t I?; are you not? / aren’t you? is he not? / isn’t he? etc.
Tiempo pasado:
Afirmativa: I was; you were; he / she / it was; we were; you were; they were.
Negativa: I was not / I wasn’t; you were not / you weren’t; he / she / it was not // he / she/ it wasn’t; we were not / we weren’t; you were not / you weren’t; they were not / they weren’t.
Interrogativa: was I?; were you? was he ? / was she? / was it?; were we? were you? were they?
Interrogativa negativa: was I not? / wasn’t I?; were you not / weren’t you?; was he not? / wasn’t he?
Las formas son las mismas cuando be se usa como verbo ordinario. Los otros tiempos siguen las reglas que rigen para los verbos ordinarios. Pero be no se emplea en la forma continua, excepto en la pasiva y como se explicará más adelante.
2. Uso de be para formar tiempos
be se usa en las formas activas continuas: «He is working» / «He will be working,» etc., y en todas las formas pasivas: «He was followed» / «He is being followed.»
Notar que be puede usarse en las formas continuas en pasiva:
Activa: «They are carrying him.»
Pasiva: «He is being carried.»
A Practical English Grammar (A.J. Thomson & A.V. Martinet) 