The phrase "acted as principal" is correct and usable in written English.
It can be used in contexts where someone is taking on the role or responsibilities of a principal, such as in a school or organization.
Example: "During the absence of the school principal, she acted as principal and managed the daily operations."
Alternatives: "served as principal" or "functioned as principal".
In 1672, during the absence abroad of Arlington and Sir William Coventry, Clifford acted as principal secretary of state.
Hillary Rodham Clinton did not make the morning announcements, patrol the cafeteria or give demerits yesterday when she acted as Principal for a Day at two Brooklyn schools.
He has acted as principal in over $50 million of real estate transactions, from homes to office buildings and hundreds of acres of land.
Preedy acted as principal fundraiser and organiser of the club, dubbed Barnsley St Peter's F.C., and even played in its first match.
Barakat has acted as principal investigator on numerous large-scale conflict and recovery research projects for the World Bank, the EU, U.K. Department for International Development (DFID), the Office of the U.N. High Commissioner for Refugees, The Institute of International Education, United States Institute of Peace, the International Labour Organization, and others.
LS designed this study, acted as principal researcher, collected and analysed data and wrote the first draft of the paper.
Traditionally, banks and investment banks acted as principals or agents, matching capital in search of economic return with borrowers needing capital to earn a real return on economic activity.
It allows the manager to act as principal for the ma-jority of shareholders in dealing with a minority.
The modeling results suggest that the hydrate and free gas interface acts as principal boundary for mode conversion from compressional (P) waves into converted shear waves (PS).
Temporal and spatial variations in the rate of basin subsidence govern the generation of accommodation space, whereas the rate and style of sediment supply govern how available accommodation is filled; together these parameters act as principal controls that dictate the gross-scale pattern of fluvial sedimentation.
"The opinion makes clear that those criminals who act as principal culprits behind the scenes to organise, direct, and plot as well as those who actively participate in inciting, coercing, enticing, abetting, or assisting others to carry out self-immolations, will be held criminally liable for intentional homicide," the paper said, according to a translation on the Dui Hua website.
