The principal parts of a verb are its present tense, its present participle, its past tense, and its past participle. The present tense of a regular verb is also sometimes called its infinitive or base form. The present participle is generally used to describe actions that are ongoing. The past tense and past participle of a verb are sometimes spelled the same way; the difference with the past participle is that it includes a modifying word or an adjective that can slightly alter the precise meaning. An irregular verb is one that does not follow all of the same grammatical conjunction rules when it comes to its principal parts, and these exceptions can often require additional practice and memorization.
A standard regular verb follows a set of rules for its principal parts that is often fairly straightforward. Forming the past tense of one of these verbs usually involves adding "-ed" or sometimes just "-d" to the end of its present tense. The past tense of the word "walk" would be "walked" according to this rule. Applying the present participle rule would normally entail adding "-ing" to the end of the present tense, creating the word "walking" as the present participle of "walk." A modifying word is necessary to create the past participle out of the past tense of this same word; two possible examples could be "has walked" or "have walked" depending on the singular or plural tense of the subject.
Irregular verbs frequently need extra attention when it comes to learning the correct usage of their principal parts. These verbs include those with different words rather than just different spellings used for their past tenses or past participles. An example would be the past tense "ate" for the present tense of the word "eat", and the past participle of this word simply adds "-en" to the end of the present tense to create "eaten."
Successful language learning requires a good foundation in grammar concepts such as the principal parts of verbs because these are essential for accurately communicating past happenings and present circumstances to others. Correctly formulating these tenses and participles of different words in written work can also demonstrate the writer's credibility. Some second-language learners can easily confuse the past tense and past participle of some verbs at first; they may say or write "I seen" when they mean "I saw," for example. Consistent study of the sometimes subtle distinctions between these grammatical conjugations generally leads to fewer of such mistakes over time.