What is the difference between de/du and un/une ?
I don't quietly understand the difference between du/de and un/une ... for example Je bois du vin and Je bois un vin ... I usually get it wrong either at listening or at translation ... Duolingo refers to du as (some of) which seems a little strange to me ... Thanks in advance :) ...
The partitive article (du, de la or des) corresponds to 'some' or 'any' in English. Just as you can say I'm drinking some wine or I'm drinking a wine in English, you can likewise say Je bois du vin or je bois un vin in French.
Answering to your complaint about un/une. You should be able to hear a difference in the "u". "une" has a more closed vowel, not existing in English, "un" has a vowel like in "burning". The consonant in "une" is a clear "n", in "un" there is hardly a consonant, the vowel finishes in the nose to produce a nasal sound.
De is a preposition by itself. If you are thinking that de is masculine and du is feminine, that is feminine, that is incorrect.
Du = de + le, which is not spoken in French, so it's always shortened or contracted to 'du'. The feminine is 'de la'.
Consider these 2 examples:
1) Je bois du lait = I am drinking/ drink some milk. (Some is de and milk is le lait)
2) Je bois de la bière = I am drinking/ drink some beer. (Some is de and beer is la bière)