Its too easy to recognize  કૃદંત in sanskrit learn this by a simple way....

There are mainly 5 types of  કૃદંત in sanskrit ...

• વિધ્યર્થ  કૃદંત 
• હેત્વર્થ  કૃદંત 
• કર્મણી  કૃદંત 
• કર્તરી  કૃદંત 
• સબંધક ભૂતકૃદંત

Below I m giving the shortcut way to find it..........

The highlighted portion is the shortcut key...

When there is અવ્યય(he ,she, it,:- प्र, यदा, तदा, सः) before the word containing य then there is  સબંધક ભૂતકૃદંત  other wise it is વિધ્યર્થ  કૃદંત .

If any question you have then ask it in comments..

See this video for deep information....