Being able to recognise where changes in mood and emotion in a script occur is important because you need to convey these changes to your audience. The meaning of the words as well as the punctuation used in the script can really help here (sometimes there are stage directions to help, too, although not usually in Shakespeare).
Actors express emotion through:
Using these methods, decide how you would express the emotion of anger.
What happens to your face, body and voice when you feel angry? How do you walk when you're in a bad mood? Which gestures do you use to show someone you're angry with them?
Now try this with other emotions, eg, surprise, excitement, happiness, sadness. See how your body, face and voice change with each emotion.
Another way to practise emotions is to do ‘mood walks’ - put all the elements together to develop a walk that represents each emotion, then greet (or growl at!) people with the appropriate tone of voice.