Downtoners generally have a lowering effect on the force of the verb or predicate (Quirk et al, 1985). They include: ‘chà yìdiǎner’ (almost), ‘chàbùduō’ (almost), ‘jǐhū’ (almost), ‘shíjìshang/shízhì shàng’ (virtually), etc., they express an approximation to the force of the verb.
Wǒ chà yìdiǎner wàng le.
(I almost forgot.) [But in fact I didn’t.]
Tāmen de hudá shíjìthe shàng shì jiēshòu le wǒmen de jiànyì.
(Their reply virtually means acceptance of our proposal.)
[Though they didn’t yet accept it.]
Tā jǐhū pòchǎn le.
(He nearly became bankrupt.) [But in fact he wasn’t bankrupt yet.]
Tā chàbùduō shì kuìxià qiúqíng le.
(He almost knelt down to beg for leniency.) [But, in fact, he didn’t.]
Zhèjiànshì jīhū bù kěnéng.
(This matter was almost impossible.) [In fact, it happened.]
This type of adverbial expresses approximation to the force of the verb; it implies a denial of the truth value of the verb, as shown by the paraphrases supplied within the brackets.
 Loar, J. K. (2011). Chinese syntactic grammar: functional and conceptual principles. New York: Peter Lang.