Partitive Articles

Here's the difference between these three ways of referring to a salad you're eating:

Je mange de la salade. -- This emphasizes the general substance/food type. More like "I'm eating salad" (as a type of food). It focuses on the act of eating salad in general.

Je mange une salade. -- This emphasizes that it's one complete salad/serving. More like "I'm eating a salad" (as a dish). Focuses on it being a single, complete portion,

Je mange la salade. -- This refers to a specific salad that has been previously mentioned or is known in context. More like "I'm eating the salad" (that particular one). Could be used, for example, if someone made a salad for the meal and you're eating it, or if you're eating the salad you ordered.

Salut Nastia,

This is tricky because it depends on what you are referring to.

1) Are you referring to a meal you already started and want to complete eating? --> La salade.

2) Are you planning to make such a meal from scratch? --> Je prépare des salade (some) 

(You are bringing together all of the ingredients required)

3) Are you placing an order in a restaurant --> Je vais prendre de la salade.

I would be interested in seeing others' comments on this issue. This is how I understand it and hope that it helps.

Bonne continuation,

Jim