create a variable named greetings and assign it hello what am i doing wrong? var greetings = "hello"

You have two options to correctly satisfy this code challenge, which highlight a very important concept in the swift programming language - type inference.

Answer method number 1:

var greeting : String = "Hello"

Here, a variable with the name 'greeting' is declared with the 'var' keyword, specifies that the value it will assign itself to is a String data type, then finally the variable 'greeting' uses the = assignment operator to assign, or store a reference to in memory, the string "Hello".

Answer method number 2:

var greeting = "Hello"

This variable declaration and assignment is interpreted by swift's compiler as exactly the same as the first answer. Swift is able to 'infer' that the variable "greeting" is of type String without us explicitly stating it's data type as String as in the first answer. It does this by simply looking at the value the variable greeting is assigned to, "Hello", sees that it is a string, then appropriately infers the greeting variable's type as String.