The phrase "I decree" is a grammatically correct and officially accepted phrase in written English.
Generally, this phrase is used to emphasize a certain decision or command. For example, you can say, "I decree that all employees must clock in by 9am every morning."
'Happy Christmas and a Fab New Year' is, I decree, the correct form.
"GUIDED by the principles of humanity, I decree: To pardon Mikhail Borisovich Khodorkovsky, born in 1963 in Moscow, and to free him from further imprisonment.
"I decree that Muslims should beware, be alert and avoid being carried away by this propaganda, which destroys religion, morals and virtues," Sheik Abdulaziz said.
Say Pope Dave said, "I decree that all people with a chronic illness or disability should be treated as lying, thieving scum until a) proven otherwise or b) they die, quite possibly from stress exacerbating their conditions".
"Not healthy," I decreed.
"Xbox, fast forward," I decreed, and the video became a blur.
And, in 1560, Elizabeth I decreed that the scholars of Westminster School should perform a Latin play every Christmas.
When my sons were toddlers, I decreed that vending machines were off limits, and they soon stopped asking for whatever was in them.
Back in the 12th century, Henry I decreed that his crown should pass to his only surviving child, the indomitable Matilda.
It soon spread to other Eastern cities, and in 542 Justinian I decreed that its date should be moved back to February 2 (40 days after Christmas).
It was probably in 1305, when Edward I decreed that 1 inch (2.5 cm) should be the measure of three dried barleycorns, that English shoe sizing began; thus, a child's shoe that measured 13 barleycorns became size 13.
