The If function checks the first argument and returns the second argument if the first evaluates to true. The third argument is returned on false.

The And function returns the logical 'and' of the arguments.

The IsBlank function returns true if the argument is empty and false otherwise.

The IsError function returns true if the argument is contains an error and false otherwise.

The IsLogical function returns true if the argument is a boolean and false otherwise.

The IsNumber function returns true if the argument is a number and false otherwise.

The isText function returns true if the argument is text and false otherwise.