What is the subjunctive? Is it another verb tense? How can I incorporate it into my French A-Level writing/speaking?

The subjunctive is a mood, rather than a tense, and while it is used in English (‘I wish that it were’, ‘I suggest that you remain where you are’), it is not very common. In French, however, it is much more commonly used. It is usually used in the subordinate part of a sentence (i.e. the second part of a sentence) and is often introduced by que. The word ‘subjunctive’ should automatically spark other words in our heads when we see it, such as ‘subjective’, ‘unreality’ and ‘subject’, which will be helpful later when it comes to identifying when to use the subjunctive mood.
At A-Level, examiners are looking for your ability to correctly conjugate verbs in the present and perfect subjunctive and successfully recognise when to use the subjunctive, rather than the indicative, mood. Here are some common instances as to when to use the subjunctive:
1.   When there is a change in subject in a sentence, e.g. ‘I want you to do it’; ‘Je veux que tu le fasses’.2.   When expressing a sense of need, necessity, obligation, recommendation etc. with impersonal verbs, e.g. ‘It’s best that you leave’; ‘Il serait mieux que tu partes’.3.   When there is any subjectivity, doubt or uncertainty expressed, e.g. ‘It seems that he is right’; ‘Il semble qu’il ait raison.’4.   With expressions of emotion, such as wish, doubt, fear, uncertainty, regret, e.g. ‘I don’t think that he will be there’; ‘Je ne pense pas qu’il soit là’.5.   When using a superlative (e.g. the best/worst/first/last/only) and you’re not certain as to whether you will find it, e.g. ‘She’s the only person who would be able to help us’; ‘Elle est la seule personne qui puisse nous aider.’