The phrase 'hard expression' is correct and can be used in written English.
It is used to describe a facial expression which communicates feelings such as anger or frustration. For example: He had a hard expression on his face as he looked up from his book.
Wearing a steel-grey suit and a hard expression, he nodded as the curator made her case for the works of Andrei Busel, a street artist.
He had a sharp, lean face, with tufts of hair on his chin and above his lip, and a hard expression that could be mistaken for actionable annoyance; you got the feeling that he might suddenly pull a ball-peen hammer from beneath his blanket and bop someone on the head, but, of course, he was not likely to do any such thing.
He took his position at the oars, then waited with a hard expression while Milo and his mother climbed in under the canopy.
With her tentative movements, scrappy bangs and hard expressions, she gives us both striver and na? a woman blind to how much she yearns for until she lands in a Manhattan of fur-trimmed coats.
A smile is the hardest expression to fathom.
In 1913, Sir William Osler referred to 'Metallics', with their "aggressive, harsh nature and... hard face", whose, "expression sends a chill to the heart of the candidate, and it reaches his bone marrow [with ] the first question... .........., to be contrasted with the 'Molluscoid', the "invertebrate examiner, so soft and slushy that he has not the heart to reject the man".
In the coming months, I'd see some of them walking around with dried blood on their uniforms and a hard, tight expression on their faces.
Yet, even as these accumulate, there are occasional hints at what would become the acclaimed Hemingway mode of between-hard-covers expression.
As I walked up a pedestrian mall called Calle de la Montera, headed toward my hostel, I saw several people -- each with a haunted, hard-luck expression -- wearing sandwich boards that read, "COMPRO ORO".
In the case of a complete knock-out, this is readily handled by hard-wiring expression of the knocked-out gene to zero in the model and otherwise fitting the data as usual.
"On the December 1, in secret, without debate, and without wider consultation, Parliament pushed through new laws that censor internet porn, clamping down far harder on expressions of women's and LGBT sexuality than on straight men's," Charlotte told me, explaining the reason she's so outraged at the passing of these laws.
