Present participle
The present participle is formed by adding -ing to the base form of the verb. Note the changes in spelling:
read » reading
study » studying
grow » growing
relax » relaxing
Perfect participle
The perfect participle indicates that the time of the action that it refers to is before that of the verb in the main clause:
Having taken the wrong turn, he ended up in a dangerous neighbourhood. (having taken refers to a time before ended up: After he had taken the wrong turn, he ended up in a dangerous neighbourhood.)
Past participle
The past participle is also called the third form of the verb. With regular verbs, the past participle is formed by adding -ed to the base form. Note the changes in spelling:
look » looked
stay » stayed
bite » bitten
fly » flown
hit » hit
leave » left
swim » swum
Having been nominated three times for an Oscar, he is one of today's most acclaimed film directors.(He has been nominated three times for an Oscar, and he is one of today's most acclaimed film directors.)