Don't touch the actors and they won't touch you

The 'normal' way of making a conditional in English is with an 'if'-clause:

If you hurry up, we'll be in time for the train.
We'll be in time for the train if you hurry up. 

There are plenty of others too, of course (As long as you keep walking, we'll be in time for the train) and of course -- isn't it always -- it's much more complicated than this, but there's also a cool way of doing conditionals with and and or.

Consider this warning, which I saw at Dreamland in Margate at their Screamland Hallowe'en thing a couple of years ago:

Don't touch the actors and they won't touch you.

Poster for 'Screamland' in Margate

You could interpret that as an instruction combined with a simple statement of fact: the instruction is not to touch the actors, and the statement is a reassurance that they won't touch you, independent of the instruction. That might in fact be what is intended here, because even if you do touch the actors, they're probably still not supposed to touch the visitors.

But we're funny things, humans, always looking for connections, patterns, reasons, and causes. Those two things being joined makes us want to think that there is some meaningful link between them. It's like if someone says The car is making a funny noise and Jen borrowed it yesterday. You can be pretty sure they're blaming Jen for the funny noise the car is making, and not just telling you two unrelated facts about the car.

Generally, in an and sentence, both bits are the same type: both statements, for instance, in which case they must both be true (so for the sentence about the car to be true, it must be true that it's making a funny noise and that Jen borrowed it -- notice that the inferred link that Jen was to blame does not have to be true). Or they might both be instructions, in which case you're expected to obey both (at the same time or in order), as in Sit down and shut up. Our example sentence, about the actors, is a mix of an instruction and a statement. So we might be expected to obey the instruction and for the statement to be true. I don't know about you but I don't really know where I stand right now, as there is no obvious link between my obedience and objective truth.

It would make so much more sense if, say, the truth of the statement was conditional on me obeying the instruction. So if I don't touch the actors (obey the instruction), then it will be true that they don't touch me. And all of a sudden, we have a conditional like the 'if'-clause type I mentioned right at the top, but with and instead.

Can we do it with or, a disjunction? Well, yes we can, but it comes out as a warning or threat rather than a deal or an agreement.

Don't bother the tigers, or they'll attack you. 

Now, we still have to obey the instruction but if we don't, then the second part will be true: a punishment, rather than a reward for our obedience.

We can even do it with neither at all, just so long as it is a proper threat and not just a warning:

Touch my stuff, I'll beat you up. 

Now the instruction is an elliptical conditional. There's probably an understood 'If you' at the beginning, or else the link between the parts is the same as with and: if the first part is 'obeyed' (the person does carry out the action), then the second part is true.

Warning: extra care has been taken

Asda's smoked salmon trimmings have this warning on the packet:

Warning: Extra care has been taken to remove bones, although some may remain. 

If you scroll down a bit at the link, you can see it there. For most of the time it took me to make smoked salmon crostini this morning, I was trying to work out why I didn't like this phrasing. Eventually, I worked it out, and I think it's a real-life example of the misunderstanding that conjunctions and subordination work in different ways that I'm constantly correcting in my students' work.

Our online marking software allows you to create comments that you can use whenever you need them. Here's the one I created for this:

Whereas: introduces a subordinate clause (usually before the main clause). It is not followed by a comma, but the clause it introduces is. It therefore looks like this, where X and Y are complete sentences:
1. Whereas X, Y.
2. X, whereas Y.
And it does not look like this:
3. X. Whereas Y.
Although: works exactly like 'whereas'.
However: Unlike 'whereas' or 'although', when followed by a comma, it can introduce a sentence. Also unlike them, it cannot join two sentences unless you also use a semi-colon. If you're trying to do this with 'however', you probably want 'but'.
It looks like this:
1. X. However, Y.
2. X; however, Y. [but I would recommend 'X but Y' instead]
It does NOT look like this:
3. X, however Y.
4. X however, Y.
Therefore: works exactly like 'however'.

The substitution of however for but is the one that annoys me the most: it's pure 'big word syndrome', and sounds clunky.

Back to the salmon, they've used although when but would have been better. That would have given them the precise meaning they wanted to convey, namely that even though they've been totally diligent, there might even so be some bones in the salmon. That would work because but coordinates two clauses, so neither clause 1 (extra care has been taken to remove bones) nor clause 2 (some may remain) has more importance than the other and the whole of clause 1 and clause 2 together is interpreted as the warning.

The problem with although here is that it subordinates the clause that it introduces. In their formulation that's clause 2 (some may remain). This clause, because it's subordinated, can't be the main bit of that sentence and therefore can't be the warning. Only the main clause can be the warning, and the main clause is the one that's not subordinated, namely extra care has been taken to remove bones. They're warning me that they've taken extra care to remove bones, and as some extra information they note that some may remain. That's not right! If they really wanted to use although, they could have: they just need to make the warning be the main clause and although subordinate the real extra information (their claim of diligence):

[Although extra care has been taken to remove bones,] some may remain.