ENGA3 is coming up as you already know, so good luck with it. It's a tough paper and it's really important to know exactly which skills to use on which part of it, so think carefully about how you plan your answers.
The January paper had the following questions:
Question 2 is a language variation one, and you have to be really careful to read the question! On question 1 you were asked to analyse both texts in the first bullet point but on this question you were only asked to analyse the first text. It might not be the same this summer, so read the question carefully. For this question you were being asked to do much the same as you were in question 1 but with a focus on language variation (dialect etc.) rather than change. The other key thing is to think not just about the features of the extract (its non-standard grammar, lexis etc.) but also the views the guy is putting forward - what he means and how he conveys his ideas. The second bullet point is then asking you to do a more essay based answer on the different attitudes towards regional dialects and accents.
Question 3 is very different and you need to have a clear sense of how it's different. Whereas you had a choice of answering either 1 or 2, you get no choice here and anything from A2 could turn up - regional variety, language change, male female variation, age-related variation, social groups and language use, even world Englishes. You have to have covered all the bases just in case (or be very lucky).
The texts you are given for question 3 will be aimed at a non-specialist audience: they're not written for linguistic experts but the general public, so they will often over-simplify, misrepresent or just rant about a language issue. You're being asked on question 3 for your expert opinions as A level Language students (OK...I know...) on what these writers have said. You must pull what they say apart linguistically (breaking down word choices, sentence choices, clause structures just like you did on the first part of the paper) and then evaluate what they have said in the light of what you and others know about the issue. It's supposed to encourage you to put your own ideas forward and take part in a debate about language, so don't be afraid to offer your own views or those of other relevant experts. The topics are usually chosen to give you something to talk about, not to catch you out.
So, in the case of the January paper, the two texts present men and women as homogenous groups. Men pretty much always do this and women pretty much always do that. But that's not right, is it? Most linguistic research (and especially the most recent work by people like Deborah Cameron) suggests that while differences may occur between men and women, there are also huge differences between men and men and women and women. Gender is only one factor in a range of other ones and to claim it's all biologically determined is a load of cobblers. There are many other approaches to take too and these will depend on the topic you're given:
Texting is destroying language! No it isn't.
Political correctness is changing language for the worse! Err, no...
English is the language of the world! Kind of...but think about this too
Anyway, if you have any questions, add them as comments and I'll try to help you (unless it's between 3pm and 5pm tomorrow in which case I will probably be weeping into a can of Stella).
My top tips for Thursday (blind guesswork only, it has to be said):
Question 1: two texts from different times to compare and a discussion about language change over time
Question 2: gender related variation with some data
Question 3: texting and how it's destroying our language.