The middle ground between these two extreme cases can be indicated by adverbials expressing approximate ideas, which may take various guises:
1a. 他工作大概/可能认真。
Tā gōngzuò dàgai/kěnéng rènzhēn.
(He has probably been conscientious about his work.)
1b. 他工作不真的认真。
Tā gōngzuò bú zhēnde rènzhēn.
(He has not really been conscientious about his work.)
1c. 他工作几乎不认真。
Tā gōngzuò jǐhū bú rènzhēn.
(He has hardly been conscientious about his work.)
Obviously, the truth value of the statement ‘He works conscientiously’ is attenuated or varnished by the adverbials ‘dàgai/kěnéng/bú zhēnde/jǐhū’ (probably, possibly, not really, hardly).
[1] Loar, J. K. (2011). Chinese syntactic grammar: functional and conceptual principles. New York: Peter Lang.
