FRENCH ARTICLES
Definite vs. Partitive

The use of the definite article (le, la, etc.) and of the partitive (du, de la, de l',or a blank) in French depends upon whether or not they follow the preposition "de." "De" is a preposition when it follows expressions that require "de" before a noun, such as "beaucoup de," "parler de," and "avoir peur de."

A. Not following the preposition "de":

1) le,la,l',les: a) refer to a definite object and are translated by "the."
Ex. the dust = la poussière
  b) refer to an idea or thing in general, or to an abstract idea.
Ex. dust (in general) = la poussière; love (the abstract idea)=l'amour
2) du,de la,
de l',des:		 refer to an indefinite quantity and are translated by "some" or by no word at all.
Ex. (some) dust = de la poussière

B) Following the preposition "de" (you must memorize those verbs or expressions that are followed by the preposition "de," such as avoir besoin de, avoir peur de, and be aware when "de" is a preposition meaning "of" or "from"):

1) Expression+de + le(etc.) a) refers to a specific object ("the").
Ex. avoir besoin de la voile = to need the (specific) sail.
----beaucoup de la soupe que tu as achetée hier= lots of the soup you bought yesterday.
  b) refers to an idea or thing in general or to an abstract idea.
Ex. avoir peur des voiles, de l'amour= to fear sails (in general), to fear love (the abstract idea)
----Ils parlent des voiles.=They are speaking about sails (in general).
2) Expression + de ____ refers to an indefinite quantity ("some").
Ex. avoir besoin de voiles = to need (some) sails.
beaucoup de voiles = lots of sails.
----Ils parlent de voiles=They are speaking about (some) sails.

C. Not following the preposition "de," the articles "des, du, etc." become "de":
1) immediately preceding a plural adjective (if the adjective does not form a unity with the following noun);
Ex. des livres => de gros livres. (but: des jeunes filles)
2) When "du, de la, etc" are the direct object of a negative sentence and the noun they modify is totally negated by this sentence ,"not...any," "none" (after "être" the noun is not totally negated, so "du, etc." remain the same in the negative).
Ex. Il a un stylo. => Il n'a pas de stylos (mais: Ce n'est pas un stylo.)