How can I form the perfect tense in German?

The perfect tense is used to express things that have happened in the past in general. It is the most commonly used past tense in German.
It is used to describe something that you have done, but maybe do often and are likely to do again, eg:
The subject + auxiliary verb + the past participle, eg:
ich habe gelernt – I studied
ich (SUBJECT) habe (AUXILIARY VERB) gelernt (PAST PARTICIPLE)