English homework, help!?

Question

what are the differences between these two sentences?

1 I don't need to go to school tomorrow.

2 I needn't go to school tomorrow.

and also,

1 Did you know him? and

2 Do you know him?

When should i use DO or DID?

can somebody explain it for me?

Answer 1

For your first question:

"Needn't" is very rarely used in English nowadays. It is uncommon in British English but almost never spoken in American English. Though it's good for you to recognize it because you will find it often in literature.

For your second question:

"Did you know him?" is in past tense and "Do you know him?" is in present tense.

Answer 2

I don't need to go to school tomorrow. = I needn't go to school tomorrow.

not difference

1 Did you know him?  = past tense

2 Do you know him? = present tense

Answer 3

In the first example, the two sentences mean the same thing. Both are present tense. It's just that Americans don't use the word "needn't" very often.  It's more common among Brits.

In the second, "do" is present, and "did" is past, so that the first sentence implies that the person being spoken to may have known the other person in the past but dearly doesn't now.  Maybe that other person is dead, or maybe the speaker knows that they one lived in the same place or attended the same school.

In English, "do" and "did" (and "does") are used as auxiliary verbs in questions and negative statements, whereas other languages might express the same ideas by changing the word order or inserting a negative word into the sentence.

Answer 4

For the first two sentences, there are virtually no differences. The only difference is the fact that "needn't" is not used as commonly as "don't need to" in the Englsih used in the United States.

In the second group of sentences, the use of the word "did" implies that the action happened in the past and "do" would imply that the person still knows "him".