Section 3001. Qualifications of teachers

No person shall be employed or
  authorized to teach in the public schools of the state who is:
    1. Under the age of eighteen years.
    2. Not in possession of  a  teacher's  certificate  issued  under  the
  authority  of  this  chapter  or a diploma issued on the completion of a
  course in state college for teachers or state teachers college  of  this
  state.
    The  provisions  of  this  subdivision  shall not prohibit a certified
  teacher from permitting a practice  or  cadet  teacher  enrolled  in  an
  approved  teacher  education  program  from teaching a class without the
  presence  of  the  certified  teacher  in  the  classroom  provided  the
  classroom  certified  teacher  is  available  at  all  times and retains
  supervision of the practice or cadet teacher. The  number  of  certified
  teachers  shall  not  be  diminished  by reason of the presence of cadet
  teachers.
    3. Not a citizen. The provisions of this subdivision shall not  apply,
  however,  to  an  alien teacher now or hereafter employed, provided such
  teacher shall make due application to become a  citizen  and  thereafter
  within the time prescribed by law shall become a citizen. The provisions
  of  this subdivision shall not apply, after July first, nineteen hundred
  sixty-seven, to  an  alien  teacher  employed  pursuant  to  regulations
  adopted by the commissioner of education permitting such employment. The
  citizenship requirements of this subdivision shall not apply to an alien
  teacher  now or hereafter employed whose immigration status is that of a
  lawful permanent resident of the United States and who  would  otherwise
  be  eligible to serve as a teacher, or to apply for or receive permanent
  certification as a teacher, but for the foregoing requirements  of  this
  subdivision.
    * NB Effective until November 30, 2012