The partitive article de in French

Je ne veux pas de sucre (I don't want any sugar). When the sentence is in the negative, du becomes de: je veux du sucre (I want some sugar) → je ne veux pas de sucre (I don't want any sugar). Another example: elle boit du café (she drinks coffee) → elle ne boit pas de café (she doesn't drink coffee).

Le client veut un verre d'eau (The customer wants a glass of water). We use de after words that specify a quantity, like un verre (a glass), une tasse (a cup), une bouteille (a bottle), etc. When the word that follows begins with a vowel (here: eau, “water”), de becomes d'. Example: une tasse de thé (a cup of tea); une bouteille d'eau (a bottle of water).

Mon père achète des tomates (My father buys tomatoes). As a general rule, we use des les partitifs before a plural noun. Example: il achète des fleurs (he's buying flowers).

Marie n'a pas d'argent (Marie doesn't have any money). When the sentence is in the negative, d' replaces de l' in front of a word beginning with a vowel: Marie a de l'argent (Marie has some money) → Marie n'a pas d'argent (Marie doesn't have any money). Another example: il y a de l'électricité. → il n'y a pas d'électricité (there is electricity. → there is no electricity).

Le chef prépare du riz (The chef is preparing some rice). We use du les partitifs to refer to a quantity that cannot be counted, and it always refers to a masculine singular noun: in this case, le riz (rice). Example: il mange du saucisson (he eats sausage).

Tu manges beaucoup de légumes (You eat lots of vegetables). When specifying a quantity like beaucoup (lots), we use de before a noun that starts with a consonant. Other examples: je veux bien un peu de sauce (I'd love a little sauce); il y a trop de monde (there are too many people).

Mon ami ne boit pas d'alcool (My friend doesn't drink alcohol). In a negative sentence like this one (which uses ne…pas), we use d' to replace de before a noun that begins with a vowel (alcool) or a silent h. Examples: je ne veux pas d'épinards (I don't want spinach); il n'a pas d'humour (he has no sense of humor).

Je bois de l'eau gazeuse (I drink sparkling water). We use de l' before a word that starts with a vowel (eau, meaning “water”) or a silent h. Examples: elle a de l'ambition (she has ambition); la vache mange de l'herbe (the cow eats grass).

Il y a trop de sel (there is too much salt). When specifying a quantity like trop (too much), we use de before a noun that begins with a consonant, such as sel (salt). Other examples: elle mange beaucoup de fruits (she eats a lot of fruit); je veux un kilo de farine (I want a kilo of flour).