"An elephant is drinking water."
Translation:Un éléphant boit de l'eau.
'du' is used with masculine nouns and is a combination of both de and le: de + le = du, de + les = des and if is feminine, la, or l', it is just de - de la and de l'.
For example You would say 'du lait' because milk is masculine - de le lait/ du le lait is wrong. to say 'some food' you say 'de la nourriture' because food is feminine As 'eau' starts with a vowel, you need l' in front of it and de always goes with l' so it is de l'eau.
Hope that makes sense...?