The phrase "act mostly" is correct and usable in written English.
It can be used to describe the primary behavior or tendency of someone or something in a general context.
Example: "In this situation, people tend to act mostly in their own self-interest."
Alternatives: "primarily behave" or "mainly act".
But there's an additional factor, that even supporters of the Affordable Care Act mostly missed: the extent to which, for the first time, the Act is creating a truly functioning market in nongroup insurance.
In previous shows this Korean-American writer has devised a comic revue about black identity politics, retailored Shakespeare's "King Lear" and taken to the stage herself to perform a cabaret act mostly about death.
Vaccines now in use for diseases like polio, mumps and measles are thought to act mostly by stimulating one of the two arms of the immune system: the one called humoral or antibody-mediated immunity.
Within a few years, as technology expanded our ability to peer into the brain, it became clear that antidepressants act mostly by increasing the availability of the neurotransmitter serotonin — rather than dopamine and norepinephrine, as previously thought.
Mr. Pine, who appears in the first act mostly in bed in his pajamas and in the second act as only an observer, plays Howard as a nearly defeated man clinging to his dignity and achievement, which Jack perceives as contempt and condescension.
So far, Trademark has studded it with buildings that act mostly as a backdrop to a parklike area with two stone bridges, a pond, a creek, a 34-foot-tall community fireplace, climbable sculptures, and 10 restaurants that have outdoor seating with views of the pond, creek or village green.
The big acts mostly came during summer and for a few weeks before and after.
So, in its way, does the deliberately narrow spectrum of acts, mostly aerial in their emphasis.
The friendship story line acts mostly to tie together enthusiastically shot battlefield set pieces, innumerable episodes of intra-army abuse, and generally demonstrations of heroic endurance amid wretchedness.
"Dangerous Liaisons" was originally made in French, and no doubt it loses something in translation, especially the performance of Ms. Deneuve, who acts mostly with small inflections.
Unlike the Pirate Bay, which acted mostly as a link repository, with limited oversight or quality control, Oink would be something else entirely: a carefully curated digital archive with a fanatical emphasis on high-fidelity encodings.
