Focusing adverbials direct attention to a part of a sentence that can be as wide as the predication or as narrow as a single constituent of an element (like a pre-modifying adjective in a NP as object). They are peculiar in that their meaning applies to units of varying size and position. Focusing adverbials are realized by a very limited set of items and they can be further divided into two subsets: restrictive and additive.
The restrictive adverbials indicate that the sentence concerned is true with respect to the part focused. They are realized by adverbs, which include: ‘zhǐ’ (only, merely), ‘jiù’, ‘wéiyǒu’ (alone, solely), ‘jǐnjǐn’ (merely), ‘yóuqí’ (especially), ‘tèbié’ (particularly), ‘quèqiè de’ (precisely), ‘zhǔyào de’’ (principally), ‘shǒuyào de’ (primarily), ‘jùtǐ de’ (specifically), ‘zhìshǎo’ (at least), etc. The additive adverbials indicate that the sentence concerned is additionally true with respect to the part focused. They include: ‘zài’ (again), ‘yòu’ (again), ‘hái’ (also, as well), ‘tóngyàng’ (likewise), ‘cǐwài’ (in addition), etc. Here are some examples, in which the elements placed within the slashes are the focus:
Wǒ zhǐshì/chūqu sǎnsǎn bù/.
(I am simply going out for a walk.)
Tā zhǐ chuān/míngpái de/yīfu.
(He only wears famous brand clothes.)
Zuótiān de huìjiù/Xiǎo Wáng/méi cānjiā.
(Only [Xiao Wang] didn’t attend yesterday’s meeting,.)
Zhìshǎo yǒu/sāngè xuéshēng/jīntiān méi lái shàngkè.
(At least three students didn’t come to class today.)
In the above examples, the part of the sentence that the meaning of a focusing adverbial applies to is placed within the slashes. In (1a), for instance, the restrictive adverbial ‘zhǐ (shì)’ may focus on the predicate ‘going out to take a walk’, or only on the second VP of th predicate ‘take a walk’, namely, the speaker’s action of going out is only for the purpose of taking a walk. In (1b), the focus that the adverb ‘zhǐ’ draws attention to is as narrow as the premodifier ‘míngpái de’ (famous brand) of the object NP. The adverbial ‘jiù’ in (1c) signifies that the truth of the proposition that some people didn’t attend the meeting is limited only to ‘Xiao Wang’.
 Loar, J. K. (2011). Chinese syntactic grammar: functional and conceptual principles. New York: Peter Lang.