What's the difference between send and send?

1.send: send, send, assign, send; Verb prototype, used in the simple present tense?

You'd better send this letter by airmail.

You'd better send it by airmail.

2. send: it is the past tense and past participle of send, and it has two uses.

(1): The place where send should be used should be changed to the past tense of send.

I posted this letter yesterday.

I sent this letter yesterday.

(2): Yes, being sent means sending.

This letter must be sent before tomorrow.

This letter must be sent before tomorrow.

Extended data:

Send related phrases:

Send something to sb? Give sb sth; Send something to someone; Give sth to sb. Give sth to sb.

2. Send it back to me? Send it back to me; I will return it; I sent it back; Send it to me.

3. Send flowers to China? Send flowers to China.

4. Where to send the e-mail?

5. Send photos to the address? Send photos to this address.

6. Send me a postcard? Send me a postcard; Send me a postcard.

7. Send a sample notice? Sample sending notification

8. Send a message to? Send a message to

9. Give you a present? Give you a present.