My fifth grade teacher once said it's not what you teach, but how you teach. And as teaching is the act of imparting skill or knowledge to educate an individual, while learning is the actual act of acquiring that skill or knowledge it is highly unlikely that any teaching could occur if there is no learning.
A good example of this can be seen in the difference in most high schools in America. For instance when we look the educational standing of most schools in the country we find that the difference between a school with a higher academic average and that of a lower one is all in the method of teaching and the state of the learning environment. Take for instance charter schools. Before charter schools came along most urban kids had to make do with inexperienced teachers, bad equipment and very little attention. Put a D student from a learning environment like the one just described into a charter school where the school is allowed to choose its own curriculum, set its own standards of qualification for its teachers etc. You get an A student who takes his/her work seriously and strives to learn.
Sanda.2.
Apart from this it must be duly noted that while some may disagree that there are some individuals that cannot just be taught certain things, one must realize that its all in the way the subject being taught is presented. Therefore it sounds quite suspicious when someone says they are teaching and there is no learning occurring. One could quite possibly say that rather than say the student cannot learn one should assume the teacher couldn't teach. After all the whole purpose of teaching is to ensure that at the end of the day the day the people being taught have learnt something. Consequently if there is no learning going on then nothing is being taught and if nothing is being taught to the student in question there could be no teaching going on. Like in the words of Wole Soyinka a teacher is the light, a student with a instructed by a bad teacher is like a swimmer trying to see with a bad head lamp.