The phrase "act determines" is correct and usable in written English.
It can be used in contexts discussing the influence or impact of an action on a particular outcome or situation.
Example: "In legal terms, the act determines the consequences that follow."
Alternatives: "action dictates" or "deed influences".
"The way you act determines how you make progress.
Instead, the reason for the individual marital sexual act determines its permissibility.
The Dutch Housing Act determines that housing associations can only increase the rent for social housing once a year by a certain fixed percentage (2.5% in 2015, up to a maximum rent of €710.68 a month) and, linked to specific conditions, after measures have been taken to improve a dwelling, e.g. through the installation of solar PV panels.
How you act determines how people perceive your business.
Behavioral scientists study how the way we act determines our health, adding to information about the causes of major diseases, such as diabetes, strokes, cancer and heart disease.
Still, she's working like a baby act determined to promote herself as much as possible.
The Regulation of Investigatory Powers Act 2000 (RIPA) is the main act determining the actions of the security services.
Then, last month, the Supreme Court struck down the part of the Voting Rights Act determining which states should get extra scrutiny.
In Germany, the Law on Asylum Procedure and the Asylum Seeker's Benefits Act determine the national organization of housing.
The illocutionary force and the propositional content of a speech act determine its conditions of success and satisfaction.
In 1975, the Legislature broadly exempted itself from the California Public Records Act, determining that "records of complaints to or investigations conducted by... the Legislature" need not be disclosed.
