Task should show to assign person only

tasks should show only to person to whom it will assign.
how to achhive this

Please use User Permissions/Restrictions for this. Please refer the link to learn more.

Hope this helps.

Thanks for reply,
but I think above link is for restrict user to see specific task after creating task.
and I want setting for all user should see only task assign to them.

For that u should restrict role permission manager

Then Share the task to particular persons u want to assign