Found:

• Wackernagel's law
• Wanna-contraction
• Weak: see Strength
• Weak crossover
• Weak feature
• Weak Lexicalist Hypothesis: see Lexicalist Hypothesis
• Weak noun phrase
• Weather-verb
• Well-Formedness Condition
• WFC: see Well-Formedness Condition
• WFR: see Word Formation Rule
• Wh-in-situ
• Wh-island
• Whisper triangle: see Whispering
• Whispering
• Wh-movement
• Wh-phrase
• Wh-question
• Wh-trace
• Wide scope: see Narrow scope
• Wideband: see Spectrogram
• Window model
• Windowing
• Wizard of Oz
• Word
• Word boundary
• Word form: see Lexeme
• Word formation
• Word Formation Rule
• Word Structure Autonomy Condition
• Word Syntax
• Word-based morphology