When do I use the subjunctive?

1- What is the subjunctive? 

It is a mood (not a tense!) which expresses uncertain ideas.

2- So when do I use it? 

Set phrases with 'que' 

Negative phrases with 'que' which express emotion or doubt or other uncertainty

Phrases that suggest wanting or willing to

3- What are examples of these phrases?

A list of phrases would be provided with examples the student can recognise (i.e. topics they are learning about) 

4- How do verbs change in the subjunctive?

A step-by-step guide to conjugating regular verbs would be worked through, followed by discussing common irregular conjugations and doing an activity where translation and recognition of the subjunctive would be required. To follow up, students would then produce their own piece of writing which includes some subjunctive mood.