Research has demonstrated that poor readers may demonstrate a variety of language deficits (e.g., Adams, 1990), and children with language difficulties have difficulty reading later in life (e.g., Catts, Fey, Zhang, & Tomblin, 1999). Teachers are likely to be faced with the challenge of implementing programming to meet the needs of children with varying language needs. Therefore, teachers' knowledge of language is essential (e.g., Moats, 1994; Wilson, 1999). This study investigated which teacher variables significantly predicted teachers' knowledge of language form (phonology, morphology, syntax), content (semantics), and use (pragmatics). The Assessment of Oral Language Knowledge (AOLK; McIntyre, 2005) was administered to 236 preservice and inservice teachers. A simultaneous regression model was used to explore which teacher variables significantly predicted teachers' knowledge of language form, content, and use. Results indicated that years of teaching experience and gender accounted for 17.37% of the variance in teachers' knowledge of language form. Teachers' years of teaching experience and gender also accounted for 18.7% of the variance in teachers' knowledge of language content. None of the variables were statistically significant predictors of teachers' knowledge of language use. The importance of exploring teachers' knowledge of all three language domains, and the characteristics that influence this knowledge, to teacher training and inservicing are discussed. (Contains 3 tables.)