Overview of nano's shortcuts      
The editor's keystrokes and their functions         
File handling
Ctrl+S    Save current file
Ctrl+O Offer to write file ("Save as")
Ctrl+R Insert a file into current one
Ctrl+X Close buffer, exit from nano
Editing
Ctrl+K    Cut current line into cutbuffer
Alt+6 Copy current line into cutbuffer
Ctrl+U Paste contents of cutbuffer
Alt+T Cut until end of buffer
Ctrl+] Complete current word
Alt+3 Comment/uncomment line/region
Alt+U Undo last action
Alt+E Redo last undone action
Search and replace
Ctrl+Q    Start backward search
Ctrl+W Start forward search
Alt+Q Find next occurrence backward
Alt+W Find next occurrence forward
Alt+R Start a replacing session
Deletion
Ctrl+H Delete character before cursor      
Ctrl+D Delete character under cursor
Alt+Bsp Delete word to the left
Ctrl+Del    Delete word to the right
Alt+Del Delete current line
Operations
Ctrl+T    Execute some command
Ctrl+J Justify paragraph or region
Alt+J Justify entire buffer
Alt+B Run a syntax check
Alt+F Run a formatter/fixer/arranger
Alt+: Start/stop recording of macro
Alt+; Replay macro
 Moving around
Ctrl+B    One character backward
Ctrl+F One character forward
Ctrl+← One word backward
Ctrl+→ One word forward
Ctrl+A To start of line
Ctrl+E To end of line
Ctrl+P One line up
Ctrl+N One line down
Ctrl+↑ To previous block
Ctrl+↓ To next block
Ctrl+Y One page up
Ctrl+V One page down
Alt+\ To top of buffer
Alt+/ To end of buffer
Special movement
Alt+G     Go to specified line
Alt+] Go to complementary bracket
Alt+↑ Scroll viewport up
Alt+↓ Scroll viewport down
Alt+< Switch to preceding buffer
Alt+> Switch to succeeding buffer
Information
Ctrl+C    Report cursor position
Alt+D Report line/word/character count
Ctrl+G Display help text
Various
Alt+A Turn the mark on/off
Tab Indent marked region
Shift+Tab    Unindent marked region
Alt+V Enter next keystroke verbatim
Alt+N Turn line numbers on/off
Alt+P Turn visible whitespace on/off
Alt+X Hide or unhide the help lines
Ctrl+L Refresh the screen