को: Experiencer ~> Recipient

Used for targets of intransitive verbs of cognition, feeling, sensation, and experience.

Note: लगना, in its capacity as an intransitive verb meaning "to feel", can be used for both Experiencer-type events as well as involuntary events (constituting Theme), like getting hurt (चोट लगना).

• सुनिता
  Sunita

  को
  DAT

  बुख़ार
  fever

  है
  is

  ।
  .

  'Sunita has a fever' 001

• राजा
  king

  को
  DAT

  दुःख
  sadness

  हुआ
  happened

  ।
  .

  'The king felt sorrow.' 002

• मुझको
  I-DAT

  हिंदी
  Hindi

  नहीं
  not

  आती
  comes

  ।
  .

  'I do not know Hindi.' 003

• मुझको
  I-DAT

  यह
  this

  किताब
  book

  पसंद
  liked

  है
  is

  ।
  .

  'I like this book.' 004

• उसको
  he-DAT

  अचानक
  sudden

  से
  INS

  आवाज़
  sound

  सुनाई
  hearing

  दी
  gave

  ।
  .

  'Suddenly, he heard a sound.' 005

This includes चाहिए in the sense of wanting.

• मुझको
  I-DAT

  दूसरी
  other

  किताब
  book

  चाहिए
  is-wanted

  ।
  .

  'I want the other book' 006

Used for targets of causative verbs of sensation, cognition, etc. like दिखाना, सुनाना.

• तुमको
  you-DAT

  एक
  one

  चीज़
  thing

  दिखाना
  to-show

  चाहता
  want

  हूँ
  am

  ।
  .

  'I want to show you something.' 007