Past tense verbs indicate actions or events that occurred in the past. They can be either regular or irregular. When a past tense verb is regular, they are formed with the verb root (or base form) of a verb plus the "d" or "ed" ending; and when it is irregular, the verb does not end with "d" or "ed" and does not follow any particular patter, for example, <em>thought, known, sat, </em>and<em> slept</em> are all irregular verbs.
The verb "occurred" is a regular verb in the past tense because it is formed with the base form "occur" plus the "ed" ending. Other examples of regular verbs in the past are <em>purred, believed, typed, walked </em>and<em> moved.</em>
The speed and accleration of a car travelling in reverse and in the normal direction is the same. Therefore the measurement of its speed is still done using the metric system or via miles per hour (mph).
