The importance of information in a sentence can be emphasized by placing it at the end after a starting “what”
HOW AND WHY “what” HIGHLIGHTS INFORMATION
The word what can be used not just to ask questions but also as a kind of relative pronoun, meaning “the thing which”. It is with this second meaning that what can highlight information. To do so, it must begin a sentence where the relevant information is placed at the end after BE, like this:
(a) What causes the most stress is noise.
The highlighted information here is noise. The highlighting informs the reader that this is the main point of the sentence – what the sentence is “about”.
Most sentences contain important and less important information (see 24. Good and Bad Repetition and 156. Mentioning What the Reader Knows Already). Not all highlight the important information as clearly as (a) does – there will often be no need because clues like the normal word order of English will be enough.
What sentences (and other means of highlighting) become desirable if a writer feels that a misunderstanding is more likely. In this sense, they are “emphatic”, one of a range of possibilities surveyed in the Guinlist post 125. Stress and Emphasis. Here, I wish to look in detail at the nature and problems of highlighting with what.
THE ESSENTIALS OF “what” HIGHLIGHTING
Most grammar descriptions cover the basics of highlighting with what. As mentioned above, the word itself is a pronoun meaning “the thing which” (see 114. Tricky Word Contrasts 3, point #8). It stands for a neighbouring noun or noun equivalent (the one being highlighted – noise in [a]), just as many other pronouns do (see 28. Pronoun Errors); however, it rather unusually comes before this noun.
The highlighting use of non-questioning what has to be distinguished from a non-highlighting use that is illustrated in the following sentence:
(b) What causes the most stress must be avoided.
Here there are two verbs (underlined), just as in (a), but the second of them is not a form of BE. Moreover, what does not stand for a later noun – indeed it may not correspond to any neighbouring noun at all.
Another means of placing noise at the end of (a) is, of course, the passive voice of the verb (… is caused by noise). However, as indicated above, this is less emphatic than the use of what.
The emphatic highlighting provided by what can also be achieved by starting the sentence with it, like this:
(c) It is noise that causes a great deal of stress.
This is a different kind of it sentence from those in the post 103. Using “It” for a Subsequent Verb (it stands for a following noun rather than a verb). The difference from (b), of course, is that the highlighted meaning is no longer at the end of the sentence. Sometimes that is a good thing – some sentences read better with the highlighting first . Sometimes, however, there may be a good reason for wanting to highlight at the end.
Very many sentences can be made to begin with what. Moreover, different parts of the same sentence can be placed at the end after a starting what. Consider this:
(d) Plants absorb carbon dioxide at night.
Emphasizing plants (the subject of the sentence), this becomes:
(e) What absorb(s) carbon dioxide at night is/are plants.
Emphasizing carbon dioxide (the object), we have:
(f) What plants absorb at night is carbon dioxide.
Emphasizing absorb (the verb) is a little trickier:
(g) What plants do at night is (to) absorb carbon dioxide.
Verbs, it will be seen, need to be replaced by DO when they move to the end. They take any accompanying object (here carbon dioxide) with them. They usually lack an ending in their new position (they have the “infinitive” form, with or without to – see 148. Infinitive Verbs without “to”), unless they correspond to a continuous tense (e.g. are absorbing), in which case they keep -ing.
CONSTRAINTS ON USING “what”
The one part of sentence (d) that cannot be highlighted at the end of a what sentence is at night, a preposition phrase acting like an adverb (saying when the action of the verb occurs). However, some adverb-like preposition phrases are more flexible:
(h) What the ancient Egyptians wrote on was papyrus.
Here, the preposition part of the phrase (on) stays with the verb, but its following noun moves to the end. It is perhaps the type of meaning expressed by the preposition phrase that determines its grammar: time phrases like at night cannot be split, whereas “instrument” phrases (naming tools – see 73. Saying How with “By” and “With”) can. Others that can be split include to and for before an indirect object (see 126. Verbs with an Indirect Object) and the by associated with passive verbs. All are what I have elsewhere called “grammatical” prepositions (see 111. Words with their Own Preposition).
Ordinary adverbs like quickly, yesterday and too much also seem unable to be highlighted at the end of a what sentence. Verbs expressing states rather than actions – e.g. EXIST, HAVE and KNOW – do not easily fit there either. Nouns and adjectives in the “complement” position after BE are perhaps rarely highlighted because of repetition like the following:
(i) ?What children are is energetic.
Although nouns with a subject or object function are the easiest to highlight at the end of a what sentence, there are exceptions there too. Consider this:
(j) The British have the fewest public holidays in Europe.
As a general rule, nouns representing human beings, like the British, cannot be highlighted at the end of a what sentence. This is logical because what generally refers to things, not people. However, people nouns are not the only kind that are constrained; others include nouns for places, points in time, reasons, methods and quantities.
The inability of words to follow what, however, does not mean that they cannot be given the same kind of sentence-end highlighting that what allows.
SUBSTITUTES FOR “what”
The normal equivalent of what for highlighting human and other exceptional nouns is the + NOUN + wh-. The noun needs to have a more general meaning than that of the highlighted one, e.g. people (+ who), place (+ where), time (+ when), reason (+ why), and number (+ that). Thus, (j) can become:
(k) The people (or nation) who have the fewest public holidays in Europe are the British.
An alternative to human nouns of this kind is those (+ who).
Another use of nouns with a general meaning is for highlighting a preposition phrase. For example, at night in (d) can be emphasized like this:
(l) The time when plants absorb carbon dioxide is at night.
To take another example:
(m) The way (in which) most bulky loads are transported is by sea.
PRACTICE EXERCISE: HIGHLIGHTING WITH what-TYPE SENTENCES
In this exercise the challenge is to reword given sentences so that the underlined part in each is given what-type emphasis. Two of the rewordings can begin with what, but the others need a noun. Answers are given afterwards.
1. The Russian Revolution began in 1917.
2. Solar power will solve the energy crisis.
3. Gandhi inspired India to achieve independence.
4. Humans first evolved in sub-Saharan Africa.
5. Carbon dioxide is accumulating in the atmosphere.
6. Every six months a trip should be made to the dentist
7. Malaria is still a threat because the parasites quickly develop drug resistance.
Answers (other possibilities may exist)
1. The date/year when the Russian Revolution began was 1917.
2. What will solve the energy crisis is solar power.
3. The person who inspired India to achieve independence was Gandhi.
4. The place/region where humans first evolved was sub-Saharan Africa.
5. What carbon dioxide is doing is accumulating in the atmosphere.
6. The frequency with which a trip should be made to the dentist is every six months.
7. The reason why malaria is still a threat is that the parasites quickly develop drug resistance.