Does fertilisation happen when the tail come off he sprem?

Fertilization does not occur when the tail of the sperm comes off; rather, it happens when the sperm successfully penetrates the egg's outer layers. The tail, or flagellum, helps the sperm swim towards the egg, and its loss typically indicates that the sperm is no longer viable. The actual fusion of the sperm and egg membranes is what leads to fertilization, resulting in the formation of a zygote.