Other Classes Not Recognised By NetBeans GUI

I'm working on a University project creating a simple game using Netbeans but I'm totally stuck. I've created a number of classes to perform various methods, such as throwing back formatted text but I can't get them to work from within a Swing GUI created in Netbeans.

The Main method simply creates an instance of another class called Game which then itself creates instances of a number of other classes (textEngine, timer) and also a Swing GUI Class. The GUI appears on screen ok and I've been able to get methods working inside the GUI such as changing pictures and text when clicking a button. But I CANT get the GUI class to recognise the instances of the other classes or access their methods. I've created an instance of the TextEngine class called tEng. So I type this code in the GUI class:

textField.setText(tEng.getPhrase(2));

getPhrase() returns a String based on the number passed in the argument. But Netbeans reports an error that tEng is not recognised as a symbol despit it being a member of the same package. Creating the instance of the class within the GUI class likewise fails:

TextEngine tEng = new TextEngine();

Again the class is not recognised.