🕶 Brill tagger §

= a transformation based POS-tagger

How §

For each word in corpus:

1. Tag the word with the most likely POS
2. Choose a transformation that deterministically replaces an existing tag with a new one to improve the error rate
3. Apply the transformation

Example transformations §

#	From	To	Condition	Example
1	NN	VB	Previous tag is TO	to/TO race/NN → VB
2	VBP	VB	One of the previous tags is MD	might/MD vanish/VBP → VB