a telephone conversation

to call
to make a call
to call someone
*local
*long distance
*overseas

to reach someone by phone
to return a call

*to pick up the receiver
*to put down the receiver

the dial
the telephone buttons

*a touch-tone phone
*a cell phone

answering machine
voice mail

call display

a calling card
a telephone booth

a ring
the phone is ringing

*to dial (2)
to dial a number
to dial 123-4567
*to dial a wrong number (2)

an emergency number

a dial code
the dial tone
the beep

answer the phone

*to hold the line (2)

the line is busy

leave a message

call waiting

a telephone operator

a penpal

to exchange letters

a post office
a post service

to send a letter by mail
to post a letter

a stamp

to write a letter
to write an email
to send an email

a telegram

a fax
to fax
a fax machine