except单独用表示"除了…""除去…",前后主语属于同一类.例如:
All are here except Jam
except that表示"除了…""只是…",后跟从句.例如:
The pair of trousers fits me well except that the waist of it is a litter too small
besides指"除…还有"强调另外还有",表示"加";作幅词时,意为"此外",相当于"in addition.
except for 强调整体与局部的关系,或表示美中不足.