Suppose you want to present two arguments, one of which is even stronger than the other. For example, you might be discussing the dangers of eating too many crisps: they make you fat and the salt damages your heart. Suppose you think the salt is even worse than the calories.
Simply listing the arguments won't do, because it doesn't show that you rank one higher than the other. You need some kind of linguistic signal of the ranking, but we have quite a number of different signals, so you have to choose.
Some of the clearest but least elegant solutions use a comparative adjective with "even" - "even more serious", "even worse" and so on: "One problem is that they make you fat, but an even more serious one is that the salt damages your heart".
A very useful pattern which is worth considering simply juxtaposes the evaluation ("even worse") and the fact: "They make you fat; even worse, the salt damages your heart". An alternative to the "even worse" pattern is "worse still": "... worse still, the salt damages your heart".
These solutions have the great merit of laying your criteria out for public display, thanks to the adjective ("serious", "bad", or whatever), but sometimes the criteria are obvious.
In such cases other solutions are worth trying. For instance, consider "not only ... but also ...", as in: "Not only do they make you fat, but the salt also damages your heart". This has the desired ranking effect thanks to "not only", which implies that the fattening effect is already in focus (even if it's not). But keep your eye on the syntax after "not only" - it triggers a switch of the subject and auxiliary verb (not only do they ...) just as in a question.
A syntactically simpler solution involves a connective such as "moreover":
"They make you fat. Moreover, the salt damages your heart". (Mind the spelling of "moreover"!) Another relevant connective is "furthermore", though this is even less familiar to KS3 writers than "moreover".
Finally, you can subordinate the fat by making it into a subordinate clause or even a noun phrase: "As well as making you fat, they damage your heart," or "Besides all the calories, there's the salt that damages your heart". Or even: "Your body won't even thank you for the fat, let alone the heart-damaging salt".
No doubt your class could come up with even more possibilities - a useful exercise in shared writing.
Richard Hudson is professor of linguistics at University College, London
Geoff Barton is headteacher of King Edward VI School, Bury St Edmunds, Suffolk