The suffix चाहिए can be used to impart desire :

I want tea – मुझे चाय चाहिए

It can also be used to impart a meaning of “should” or “ought to” :

I should go – मुझे जाना चाहिए

To form the meaning “should” the suffix ना will be attached to the root verb. Then चाहिए will come after it.

When चाहता is attached to a verb, it can impart the meaning of “like” :

I like you – मैं आपको चाहता-चाहती हूँ

When चुका is an auxillary verb attached to a main verb. It can impart the meaning of something that has already been completed :

I have already done it – मैं यह कर चुका-चुकी हूँ

The suffix सका can be used to impart the meaning, “to be able” or “can” :

He can go – वह जा सका

The suffix कर can be used to denote the gerund :

Don’t drive after drinking – पीकर गाड़ी मत चलाइए

The suffix हुआ can also be used to express the gerund. However this suffix goes further. It indicates that an action occured while another action is occuring :

Don’t read while driving – गाड़ी चलाते हुए मत पढ़िए