Discuss and learn French: French vocabulary, French grammar, French culture etc.
"De" is mainly used to specify some kind of ownership :
"Le vélo de John" --> "The bike of John" (even if you would rather say john's bike)
"L'oeil de la tempète" --> "The eye of the storm"
You can also use "De" to precise a starting point, to translate "From" :
"Une lettre de ma grand mère" --> "A card from my grand mother"
"De 1987 à 1994, j'ai étudié l'économie" --> "From 1987 until 1994, I was studying economy"
"Le palais ira de là à de là" --> "The palace will go from here to there"
There are cases such as lauris mentions where de appears to have some kind of "meaning".
Unfortunately, as with the "basic" prepositions of many languages, there are a number of cases where it's more difficult to predict in advance: de tends to get used "just because it does".
The best advice is really to try and look out for where it is used. Cases that English-speaking learners can easily slip up on include:
- the "default" use of de before an infinitive in some circumstances, where it functions roughly like English "to" before an infinitive (Il préfère dormir tout de suite plutôt que de manger si tard)
- use to introduce complements that are an expression of price, number, value etc, e.g. Votre salaire sera de 3000 euros.
- surely loads of other places that will spring to mind...