The picture of English tonicity portrayed here is essentially descriptive in its intention, so there are no particular thesis to be proved or exceptionally enlightening conclusions to be reached. A number of considerations, however, can be added in order to complement and, hopefully, enrich what has been said.
A word of caution
The first point to be made is that the exceptions to the LLI principle included in this work are not exactly hard and fast rules, but tendencies, although very strong ones in general. In some of the cases, a controversy or grey area has been pointed out, such as occur in final demonstratives or indefinite pronouns beginning with every, and there are also phenomena, like event sentences, that have not been altogether explained. The hours spent looking for natural occurring examples were useful to prove that the guidelines contained in this taxonomy are not set in stone and that counter-examples can also be found. Let’s see just a small sample of them.
- Time and place adverbs:
(345) 
How important is that physical environment when you look back on your childhood? (Eleanor Wachtel; Montreal, Canada).
(346) Ordinary life actually doesn’t involve finding bodies left, right and centre (Alexander McCall Smith; Bulawayo, Southern Rhodesia).
- Embedded question:
(347) Exploring complexity and how the physical world works (BBC4 unknown speaker).
- Noun + participle:
(348) I ought to have my head examined (Michael Caine; London, UK).
In the examples above some deaccentuation processes that were likely to occur did not actually take place. However, the fact that the exceptions to the rule are not observed in one hundred percent of the cases does not diminish their weight. It only shows that the speaker has some latitude as to how to apply them depending on his or her assessment of the communicative situation. Ultimately, it gives a more accurate portrayal of the workings of a language which, as far as intonation is concerned, is so subtle.
The desirable aim is for English learners to raise their awareness of these phenomena and what they imply. This will allow them to listen to English native speakers in a different way and also to improve their own linguistic productions.
What can be achieved in this way?
There are two big areas on which a good command of tonicity would certainly have an influence.
A more natural language
The first one is related to the capacity to sound more natural, closer to the language English native speakers are used to hearing and, more importantly, the language they expect. A proper assignment of the nuclear accent within the IP will prevent our interlocutor from feeling puzzled by our way of speaking. A certain degree of awkwardness will be smoothed out, our overall pronunciation will improve and communication between the two parts will be more effective and fluid.
And, strange though it may seem to many learners, this new skill will not only work at the level of pronunciation but at that of grammar too. The reason for this is clear. Foreign speakers unacquainted with the implications that accent placement has in English in terms of meaning are much more likely to resort to the grammatical structures of their own native tongues. This usually leads them to build up sentences in their own language and then translate them more or less literally into English. It is a completely inadvisable method that usually results in constructions which are alien to the English ways. In the case of Spanish speakers, given to the nature of Spanish grammar, this often leads to a syntax that is perceived as cumbersome. What is more, it is also a process which operates in written language as much as in speaking, so the benefit to be gained from a knowledge of the tonicity system will spread to writing too.
Tonicity matters
The second important point is that English intonation has a strong bearing on the pragmatic level of the language. The link between deaccentuation and old information is strongly connected with presupposition, so it gives speakers a powerful tool they must be aware of. Writers often talk about “imposing presuppositions via tonic placement” (Carr, 2013) or “imputing knowledge.” (Wells, 2006). Let’s see an example provided by Wells. In the utterance
(349) It won’t make the slightest difference / but I shall write and complain.
the speaker is imputing to his or her interlocutor the knowledge –or opinion- that complaining won’t make any difference, and that the only thing that can be discussed boils down to just a matter of degree, which is encoded in the superlative slightest. As Wells says, by leaving the word difference out of focus, “the speaker forces this implication on the hearer”. So, a good command of tonicity will certainly help foreign speakers of English to avoid what professor Francis Nolan referred to as “unintended meaning” or even “inadvertent offence” and, by the same token, it will allow them to improve their communicative skills.
How should all this be taught?
It is true that a good use of the pragmatic level of the language requires a very proficient speaker. This wouldn’t be a problem if pronunciation were seriously taught from the beginning. But pronunciation has always been something of a poor relation to grammar and vocabulary. There is a generalized perception –one which is particularly strong in Spain- that pronunciation matters can be blithely spared without any harm to the language. But it is a false perception [1], as I hope to have shown throughout this work. And, at any rate, there is a very simple question that should be asked: why must English students become experts in the four types of conditional and embedded questions and all sorts of grammatical niceties and remain ignorant of so fundamental a principal as the LLI rule? It does not take that long to teach it, after all.
Nevertheless, we usually teach and learn wh-questions without the slightest mention to its intonation pattern. We are used to reading books about phrasal verbs and idioms which provide no indication of where the main accent must be placed. And learners are taught relative clauses and embedded questions without having a clue about how to utter them.
This dissertation is meant to be a good picture of how grammar, meaning and intonation are closely intertwined and equally important. So I should like to finish this work with a call for a more integrative approach to English teaching, one in which pronunciation in general, and the LLI rule and its exceptions in particular, have a more relevant place.
[1] Even at the risk of being overly insistent, I will take advantage of this sentence to keep preaching the LLI rule. The reader, in this case, has to deaccent the word perception –the given– in her or his mind and place the accent on false, which constitutes the new.