Unexpected adverbials

Liliane Haegeman has been here at Kent all week on an Erasmus teaching mobility visit. She's been giving four seminars on adverbial clauses, including among other things the difference between what she calls 'central' and 'peripheral' adverbial clauses. Central adverbials modify the event itself, so in this case the 'while' clause tells you the time during which the main event happened:

I took out the rubbish [while you were watching telly] 

Peripheral adverbials, meanwhile, don't tell us about event time or anything like that, but are more about the relation between the clauses or speaker attitude. In this case, the 'while' clause gives a contrastive or concessive meaning: 

I’m quite active, [while he is a total slob] 

These clauses have various properties that distinguish them. One of these properties is the tense of the verb. Central adverbial clauses (e.g. expressing time) have the same tense as the main verb, or if they don't, they're interpreted as doing so. Here, there is a future marker 'will' in the main clause, and the 'while' clause has present tense 'watch', but it's interpreted as happening at the same time as the main clause.

I'll take the rubbish out [while you watch telly]

A peripheral (e.g. contrastive) adverbial with different tenses is interpreted as being two different times:

I was fortunate to get full funding for my degree, [while he has to borrow a student loan]

The 'full funding' happened in the past (with past tense 'was') and the 'borrowing' is now (present tense 'has').

All of the above is paraphrasing what Liliane told us in the first seminar. She also said this this is something that you specifically have to tell learners of English, that they have to use present tense in this kind of clause. 'If' clauses are the same, in that they have two meanings:

If you don't understand this part, you won't be able to follow tomorrow's seminar. [if = condition]

If you didn't understand, why didn't you raise your hand and ask? [if = assumed background]

The conditional one is the one where the tense should be present even if the main clause is future, as it is here. Then, at the end of the seminar, Liliane was talking about the following one the next day, and she said this:

Even if you won't come back to the class, you have the handout. 

For this to be a normal conditional, it needs to be present tense 'Even if you don't come back'. But Liliane used the future tense marker 'won't', and then all of a sudden it was forced into the assumed background interpretation: 'Even though I understand it's the case that you won't come back...' where the implication was that she knew that we wouldn't return, and so she had given us the handout, when in fact the meaning was that she thought we would but if we didn't, we had the handout.

Another example of the same thing is a little more complicated because you need to know about Dutch word order. Dutch has 'V2', which means that the finite verb is the second constituent in the clause. So it can look like English, where you have the subject, then the verb, then the object, or it can be some other part of the sentence before the verb, like the object or an adverbial clause like the ones we just talked about. Now here's the thing: only the central adverbials can be this first element before the verb. If it's the other kind, then it doesn't 'count' and you need something else to be there, like the subject. Look at this, where the verb is in bold (example from the seminar handout):

Dutch: [Als het je interesseert,] er zal in Parijs ook een vacature zijn.
Word-for-word: If it you interests, there will in Paris also a vacancy be.
Idiomatically: 'If you are interested, in Paris there is also a vacancy.'

The 'if' clause is the kind that gives you background info, that doesn't count, so you have something else (the subject 'there') before the verb 'zal', which is now the third constituent. If you swap the order and have 'Als... zal er...', namely 'if... will there' where the 'if' clause is the one element before the verb in normal second position, it magically gets forced into the interpretation where the 'if' clause is a real conditional - the vacancy only exists if you're interested in it!

(NB: I've massively over-simplified this, and much of the week was spent learning how lots of this has interesting exceptions, and I've conflated two types of clause, etc etc. I've also paraphrased Liliane's work to write this, so consider this a citation.)