There are a lot of abbreviations which have been used in Morse communications, but we can cut this down for use in amateur radio and I am only going to mention the ones that you would find in a normal contact with another radio amateur. You can visit Kent Morse Keys for comprehensive information on abbreviations and also a comprehensive list of  “Q” codes.

• ABT About ADR Address AGN Again ANT Antenna
• BK Break (Break in transmission inviting the other station to reply or can be used to break into an existing QSO between two stations, though only send BK once in a break in transmission and wait to be invited to join) B4 Before
• C Yes, Correct CFM Confirm CK Check CQ Call Any Station CS Call sign CUD Could CUL See You Later CUZ Because CW Continuous Wave CX Conditions
• DE From DN Down DR Dear DSW Good Bye in Russian DX Distance
• ENUF Enough ES And
• FB Fine Business FER For FM From FREQ Frequency FWD Forward
• GM Good Morning GA Good Afternoon or Go Ahead (depending on context) GE Good Evening GN Good Night GB Good Bye GND Ground GUD Good
• HI Humour (usually sent twice) HR Here HV Have HW How
• K Over KN Over but only the station named should respond
• LID Poor Operator
• MNI Many MSG Message
• NIL Nothing NM Name NR Number NW Now
• OB Old Boy OC Old Chap OM Old Man OP Operator OT Old Timer
• PLS Please PSE Please PWR Power
• RCVR Receiver RFI Radio Frequency Interference RIG Radio Apparatus RPT Repeat RPRT Report RST Signal Report Format (Readability Signal Strength and Tone) RX Receiver
  
• SN Soon SRI Sorry STN Station
• TKS Thanks TMW Tomorrow TNX Thanks TU Thank You TX Transmit or Transmitter TXT Text
• U You UR Your URS Yours
• VY Very
• W Watts WK Work WL Will WID With WUD Would WX Weather
• XCVR Transceiver XMTR Transmitter XYL Wife
• YL Female
• ZX Zero Beat
• 72 Best Wishes (used by QRP operators) 73 Best Wishes 88 Love and Kisses