The term 'particle' is often used for a variety of minor function words that do not fit easily into larger, more familiar lexical categories (noun, verb, preposition, etc.), and syntacticians often separate these due to their unique functions that distinguish them from other words. Traditional English grammars and instruction often conflated these with other word groups, not realizing their unique syntactic properties or pragmatic functions. As such, 'particle' has seemingly become somewhat of a dumping ground, so to speak, for function words that syntacticians do not not what to do with; however, there are valid reasons for separating them, as each group performs unique functions. The exact classifications may depend on the particular linguist or theoretical paradigm, but here is a general list.
1 Syntactic particles
These are strictly syntactic categories, based on syntactic criteria.
1.1 Phrasal verb particles
These are the so-called adverbial adjuncts of phrasal verbs, which are not really adverbs, nor are they prepositions, in phrases like turn it on, go about, get around, get over. They are mostly recruited from the class of prepositions, but are not used in these verbs as prepositions. While they act as modifiers of sorts to the main verb, they do more, in that often the whole verb is a metaphorical extension of the original verb and preposition. For example, get over it (e.g., recover physically or emotionally) is metaphorical, and not semantically a sum of the constituent parts. The syntactic behavior is neither prepositional nor adverbial, e.g., in that they may move (turn on the radio = turn the radio on) and are often stranded at the end of a sentence (e.g,. get it on). Rather, they serve to form a compound verb. Phrasal verbs are essentially a type of compound verb.
1.2 Negative particles
The function words no and not do not act like adverbs, strictly speaking. Their sentence positions can differ from the placement of other adverbs, and their function is not so much to modify a verb or adjective, in the typical sense of 'modify,' but to negate it.
1.3 Infinitive particle
The function word to in infinitives (e.g., "I want to go") does not function as a preposition, as it is used to form a tenseless, uninflected verb. It functions more like an auxiliary verb, because (1) it occurs in the same position before main verbs as do other auxiliaries, and (2)it can be used anaphorically like other auxiliary verbs, i.e., it acts as a pro-form to avoid repetition of a verb phrase. (Anaphors and pro-forms stand in for other words, e.g, pronouns standing in for full nouns.) See Pullam (1982) and later citations thereof.
- A. Do you intend to go to the party?
- B. No, but I want to. (=want to go to the party), cf.
- B. No, but I should. (=should go to the party)
1.4 Infinitive subject marker for
In some sentences, for does not function as an actual preposition, but rather, acts to mark the subject of an infinitive.
- For him to go to that country right now would simply be an unjustified risk.
- I arranged for him to meet a nice, suitable person.
1.5 Complementizer particles
The complementizers introduce complement clauses and subordinates them to their main clauses. The most common is that, as well as others like what in embedded questions.
- I know that you did something last summer.
- I know what you did last summer.
2 Syntactic-pragmatic particles
These are categories based on both pragmatic, functional criteria and syntactic criteria. Some of these tend to overlap with accepted syntactic categories, and these classifications may be more open to debate.
2.1 Discourse particles
Discourse particles are words like well, oh, uh, y'know, like, okay, and may be considered to be part of a larger category of discourse markers or discourse connectors (e.g., but, though, since, and...). Discourse particles generally are outside the main clause structure, and are often separated from the clause by a minor intonational juncture or pitch fall; they also contain almost no inherent meaning, and their interpretation is largely pragmatic and contextual.
2.2 Focus particles
This group may overlap with conjunctive adverbs and other adverbs in their traditional classifications, but may arguably form a separate category due to their unique pragmatic functions. They serve to emphasize a noun, verb or other set of information, or indicate additional information beyond that of the marked noun, verb, etc. For example, also, too are additive markers ("He also brought a bottle of wine"), and words like even, especially emphasize the marked item via implicature (König, 1991). E.g.:
- He even brought a bottle of wine.
- Especially noteworthy was the unusual gift.
In the first sentence, even sets up an implicature - he could have brought, or did bring, other items, but in addition, he unexpectedly brought wine. In the second sentence, especially likewise modifies noteworthy by implying it goes beyond normal noteworthiness.
- Pullam, Geoffrey. (1982). Syncategorematicity and English infinitival to. Glossa 16(2), 181-213.
- König, Ekkehard. (1991). The meaning of focus particles. Routledge.