The phrase "a previous commitment" is correct and usable in written English.
You can use it when referring to an obligation or engagement that was made before the current situation or request.
Example: "I'm sorry, but I can't attend the meeting because I have a previous commitment."
Alternatives: "an earlier obligation" or "a prior engagement."
A spokesman said Mr. Biden had a previous commitment.
The framework gives structure to a previous commitment on defence and counter-terrorism measures.
She returned with a glimmering engagement ring, kept from a previous commitment.
The acclaimed actress Fiona Shaw stepped in, but had to juggle it with a previous commitment.
Staff members were left to answer analysts' questions, and they said Mr. Hassan had a previous commitment.
Families opting to fly soon often had a previous commitment: nonrefundable plane tickets, a wedding, a much-needed vacation.
The commentary was a reinterpretation of the previous commitment to "si hua," roughly translatable as the "four changes". The four changes, widely heralded in the early 1980's and written into the 1982 party constitution, aimed to make party officials more revolutionary, more youthful, more educated and more competent.
With Google expanding its mobile-phone and computing businesses, antitrust regulators have started an inquiry into directorships that straddle both companies.Rupert Murdoch said he expected that all of his websites would charge users for access within a year, despite his previous commitment that only some sites would experiment with such charges.
But the $17,000 price is important, because it signifies a betrayal of Apple's previous commitment to producing high quality products at a mass-market level.
Finally, in a May 23 , 2005 USA Today article that highlighted the presidential hopeful's peculiar status as a Massachusetts Republican, Romney acknowledged to a reporter that "I'm in a different place" from his previous commitment not to challenge Roe v. Wade.
Two weeks later the UN wrote, asking Australia to reconfirm its previous commitment; within a month, Cabinet reaffirmed the commitment of a decade earlier.
