Jawaban:

The different use of "to be" in sentences depends on two things:

1. The subject of the sentence

Example:

I am here

You are here

He is here

Different "to be" because of different subject (I/You/He)

2. The tense of the sentence.

I am reading Harry Potter novel at the moment. (present continuous tense)

I was reading Harry Potter novel when my mother arrived last night. (past continuous tense)

I have been reding Harry Potter novel for three hours now. (present perfect continuous tense)

I will be reading Harry Potter when you arrive home tomorrow morning. (future progressive tense)

In this case different "to be" is used because of the difference in tense.

Penjelasan:

Ada 8 bentuk "to be" yang dikenal:

is/am/are

was/were

being

been

be

Penggunaan "to be" yang berbeda-beda adalah tergantung pada:

1) subjek kalimat

2) tense kalimat

LIhat contoh di atas.

Semoga bermanfaat