Why teachers need knowledge in mprphology and phonology?
Because these are the structures of language. The concepts are useful for understanding and teaching language arts. Unfortunately, many of our teachers were not, themselves, properly grounded in these areas and now they are trying to teach without the proper foundation. This does not mean they were stupid, just were not completely prepared. I was fortunate to have a good background from first grade through post graduate level. I have always had a high success rate with my readers. However, there were times when I shut the classroom door and covered the window when we were doing phonics, spelling, word study etc. because the bureaucrats were hung up on sight words only.