It's fairly common to find incorrect verb forms in real-world language. For example, the correct form of is our children learning? is are our children learning? The verb is should only be used with singular nouns, while are is for plural nouns, such as children. We can correct these mistakes by creating verb correction mappings that are used depending on whether there's a plural or singular noun in the chunk.
We first need to define the verb correction mappings in transforms.py. We'll create two mappings, one for plural to singular and another for singular to plural:
plural_verb_forms = {
('is', 'VBZ'): ('are', 'VBP'),
('was', 'VBD'): ('were', 'VBD')
}
singular_verb_forms = {
('are', 'VBP'): ('is', 'VBZ'),
('were', 'VBD'): ('was', 'VBD')
}Each mapping has a tagged verb that maps to another tagged verb. These initial mappings cover the basics of mapping is to are, was to were, and vice versa.