De is one of the first Portuguese prepositions you should learn because it’s used extremely often in a variety of different situations. De can correspond to many different English translations, depending on the context.
OnEstás de férias em Agosto You are on vacation in August
No English Preposition
Certain verbs, such as those shown below, are often followed by “de”, even in places where you would not use a word at all in English.
When “de” is combined with the articles a, o, as, or os, they become da, do, das, or dos.
As we learned in the Possessives unit, “de” can also be combined with ele, ela, eles, or elas, to become dele, dela, deles and delas to indicate possession in the 3rd person:
A caneta é dele The pen is his
O projeto é delas The project is theirs feminine