That is called a party crasher and if someone wanted to ask you to an event they would. To crash a party is not only rude but doesn't make a very good friend.
Do you have to? No Should you? If you consider them a friend, yes. If you don't consider them a friend? No. Common courtesy would be to invite them if you went to theirs.
I was invited to my friend's birthday party.
Depends on the situation. Invited TO means you're invited to a place, like a party or a friend's house. Eg. You have been invited to a party down the road. <:D Invited FOR means you're invited for something like tea or coffee, mainly things not to do with caffeine :P Eg. You have been invited for tea by a friend.
I have been invited to the party.You can add the agent if you want to = by someoneI have been invited to the party by someone .
If you're invited, then yes. If you're not invited, to heck with her.
When someone says something was an eye opener, the meaning is that whatever was done or said, made them aware of things that were not known to them before. For example if one friend was not invited to a party and everyone else was, it would should the friend who was not invited that they were not as good friends as they thought. This would be an eye opener.
you have freinds?
The one word for a person who has not been invited is the gatecrasher.
The Joker would not invited.
you invite the person to be a friend and then your teacher will approve them to be a friend then the person who got invited to be a friend they will approve you to become a a friend and your their friend
This person you invited must become a member before you can get crowns.
Nothing. If it was a true "Ninja Thing" you wouldn't have been, 'invited' To be 'invited' says someone asked you and Ninja's do not 'ask'.