Complex sentence: She often appears to dislike Clifford and criticises him for minor accidents caused by his size, but occasionally she shows she really does like him and on the whole she is very friendly and seldom actually means to be insensitive.
Split into simpler sentences: She often appears to dislike Clifford and criticises him for minor accidents caused by his size, but occasionally she shows she really does like him. On the whole she is very friendly and seldom actually means to be insensitive.