Respostas
verbo to be no presente:
am - usado quando o sujeito é I
is - usado quando o sujeito é he/she/it (3ª pessoa do singular)
are - usado quando o sujeito é you/we/they
verbo to be no passado:
was - usado com I/he/she/it
were - usado com you/we/they
para botar uma frase que tenha to be na interrogativa, basta passar o to be para trás do sujeito:
carlos is fishing (carlos = ele = he, por isso to be tá como"is")
is carlos fishing?
jennifer is helping us (jennifer = she)
is jennifer helping us?
they are running
are they running?
para passar uma frase com to be para negativa, basta colocar "not" depois do to be, ou contraído com ele.
contrações do to be + not:
am not (único que não tem contração)
isn't
aren't
wasn't
weren't
i am kidding - i am not kidding
she is trying - she isn't trying
they are powerful - they aren't powerful
we were there - we weren't there
i was the only one - i wasn't the only one