As used in this part, the following definitions apply:
(1) "American sign language" means visual American sign language, tactile American sign language, or protactile American sign language.
(2) "Department" means the department of public health and human services provided for in 2-15-2201.
(3) "English" means spoken English, written English, or English with or without the use of visual supplements, cued speech, or manually coded English.
(4) "Language" means the use of American sign language or English.
(5) "Language developmental milestones" means milestones of development aligned with the existing state instruments used to meet the requirements of 20 U.S.C. 1414(b) for the assessment of children from birth through 8 years of age.