“In linguistics, an adjunct is an optional, or structurally dispensable, part of a sentence, clause, or phrase that, if removed or discarded, will not otherwise affect the remainder of the sentence. Example: In the sentence John helped Bill in Central Park, the phrase in Central Park is an adjunct.” (Wikipedia)
Perhaps the biggest categories of adjunct are place (where – as in the example above), time (when), manner (how) and reason (why). But there are more. In A student’s introduction to English grammar, Rodney Huddleston and Geoffrey Pullum list: manner, place, time, duration (how long), frequency (how often), degree (how much), purpose, result (so ~), condition (if ~) and concession (although ~). I would also add how many times.
When I was creating my grammar summary sheets last year, I got wondering if there was any logical order in which to list these. The approach I took was to consider how much information is or might be required in each category.
The shortest answer to where? is ‘here’ or ‘there’, followed by ‘at/in/on NP’. Likewise, the shortest answer to when? is ‘now’, ‘then’, ‘yesterday’, ‘today’ or ‘tomorrow’, followed by ‘at/in/on NP’. Where and when often travel together. If I say to you ‘I will meet you’, the first question or two which you are going to ask is/are either ‘where?’ or ‘when?’ or both. The question then is, which one do we put first? Do we say ‘I will meet you at the party tomorrow’ or ‘I will meet you tomorrow at the party’. My native speaker intuition says that the former is the default. Place is a concrete concept and time is an abstract one.
The answer to how? is ‘well’ or ‘badly’, followed by ‘with NP’ or ‘by V-ing’. The answer to how much is ‘a little’ or ‘a lot’. How many times, how often and how long overlap. The answer to how many times? is ‘x times’, to how often?, ‘x times per time period’ (also ‘never’, ‘rarely’, ‘sometimes’ etc) and to how long?, ‘time period’ or ‘from (time) to (time)’.
Reason, result, condition and concession standardly require a complete clause after the conjunction (traditional grammar)/preposition (Huddleston and Pullum). Reason and result are opposite and equivalent: ‘Because it was raining, we went home’ v ‘It was raining, so we went home’. (Note that the first can be reversed (‘We went home because it was raining’) but the second can’t (*‘So we went home it was raining’). Concession and condition have the same sentence structure as reason, but condition creates a different meaning: ‘Because it was raining, we went home’, ‘Although it was raining, we went home’ and ‘If it was raining, we went home’.
So my order has been as I have discussed them above: where, when, how, how much, how many times, how often, how long, why (reason), result, concession and condition.
What got me thinking about this again recently was a sentence which two students wrote last week as part of a grammar exercise: ‘A blue fat cat chased a injured beautiful bird (yesterday) (in the kitchen) (in fast speed) (for 2 hours) (because the cat has never seen such a beautiful bird)’ (my bracketing).
Another way of sorting adjuncts is the order in which they are usually placed by native speakers. I have found very little about this online. After a brief analysis, I have tentatively concluded that how etc come before where and when:
I will talk to you quietly (how) at the party tomorrow.
I will talk to you a lot (how much) at the party tomorrow.
I will talk to you once (how many times) at the party tomorrow.
I will talk to you once an hour (how often) at the party tomorrow.
I will talk to you for an hour (how long) at the party tomorrow. (or I will talk to you from 8 to 9 at the party tomorrow.)
But the students wrote ‘in fast speed’ (that is, ‘at top speed’) (how) and ‘for 2 hours’ (how long). I can’t immediately decide between ‘at top speed for 2 hours’ and ‘for 2 hours at top speed’. I would have to search for real-life examples in a corpus before I could decide.
Possibly ‘how’ comes second each time:
I will talk to you (a lot) (quietly). v I will talk to you (quietly) (a lot).
I will talk to you (once) (quietly). v I will talk to you (quietly) (once).
I will talk to you (once an hour) (quietly). v I will talk to you (quietly) (once an hour).
I will talk to you (for an hour) (quietly). v I will talk to you (quietly) (for an hour).
Searching online, I found a paper by Huddleston and Pullum (a draft for the second edition A student’s introduction), but it doesn’t actually address the question of order within sentences. They list adjuncts in approximate order of ‘syntactic integration’, first those which ‘are less likely to be set off by commas or pauses’, followed by those which ‘are considerably more likely to … be flanked by commas in writing, and by slight pauses in speech’.
I also found a book titled Adjunct adverbials in English by Hilde Hasselgard. According to the index, available online, she considers, apparently in more detail than I need, ‘Order according to syntactic obligatoriness and scope’, ‘Order according to weight and complexity’, ‘Order according to semantic categories’ and ‘Conflict and interaction between ordering principles’. So there’s possibly no single, simple answer to the question of order.
One thing which distinguishes adjuncts from subjects, verbs, objects and complements is that there can be a potentially unlimited number of them in a row, and the more there are, the more possible orders exist. There is no doubt that adjuncts can be ordered relatively freely, and some can be moved elsewhere in the sentence, either at the beginning or with the verb, which Hasselgard also considers, but which is too much for this post (almost a thousand words already).