 This development has also been termed "organic grammar", in which the development of functional categories develop from Verb Phrase (VP)→ Inflection Phrase(IP)→ Complementizer Phrase (CP).The phases have been termed the "Bare VP Stage", the "Underspecified VP Stage" and the "Agr-P Stage"  The controversy surrounding the MTH has to do with methodological problems and theoretical problems which emerge in the hypothesis.With regard to the methodological problems, the MTH has issue pertaining to "performance" vs. "competence" in data collection.