Past, Infinitive, & past participle
The major problem in the correct use of verbs is the choice of the correct past and past participle forms of irregular verbs. Since irregular past tenses and past participles are formed in a variety of ways, you must know the principal parts of speech of each irregular verb.
An example would be like with the word ride.
• If you are going to do it then you use the infinitive ride
• If it already happened then you use the past version rode.
• In order to be possessive you would use the past participle form (have) ridden.
*This information was provided by Warriners English Grammar and Composition)