Odd man out

What is wrong?

One of these words doesn't 'belong' in the group.  Which One is it? 1. dad, mum, brother, teacher  2. my, he, we, they 3. felt-tip, ruler, pen, pencil 4. John, Peter, friend, Max 5. desk, board, girl, window 6. yellow, blue, red, pen 7. rabbit, budgie, dog, cat 8. sister, morning, tea, six F  I   N     D T  H    E A  N   S    W      E        R HERE: 1. TEACHER 2. MY 3. RULER 4. FRIEND 5. GIRL 6. PEN 7. BUDGE 8 SISTER