That really depends on what type of parents you have. Since you are asking a question like this, your parents are most likely strict, so this is what you can try.
The best way to convince them is by you doing work for your parents so they are pleased and may reward you in some way for the work you have done. For instance, you could try doing specific chores around the house, get good grades, etc.
ask say your doing bad at school it worked for me
well, you have to tell your parents that you will take care of the little baby and wake up at night to feed it and stuff. Say, it will make your mum younger, and it will be a wonderful opportunity for you to learn how to take care of a little baby.
Say that you'll pay for it yourself, If they say no, Then ask why, You need a good reason, Not "because"
What you must do is act like you really want one, go to the library and check out books about how to care about a gerbil, then "read" them. Then say you will take care of it and stuff, and possibly pay for it.
There are many people in the world who will try to persuade you. Your parents and teachers will try this for example.
Just say it will be a good experience for when your older and the cell phone part say it saves them buying you one. :) <3
easy just say that boys are harassing you or say you feel that a teacher is hitting on you and just want to move school before things get worse worked for me my parents moved me from my school straight away
Tell them how responsibly you will use it
I wish I knew. :'(
no
show responsibility. ask if you may ask why calmly. if they say no, say okay. it isn't the end of the world.
If you want to persuade your parents to allow you to make a website, start by talking to them honestly. Tell them why it is important to you, and show them you can be responsible about the website as well.