Nonstandard dialects often use the same form for the past tense and past participle of irregular verbs for which the standard language has distinct forms. One possible reason would be that some speakers have a nonstandard system of verb qualifiers (tense, mood, and aspect markers) in which the past tense/past participle distinction is functionally redundant. Data on spontaneous speech in Britain in the 1990s partly supports this by showing marked regional variation in the use of the Perfect construction. However, some nonstandard past tenses cannot be explained in terms of a nonstandard qualifier system.