The prepositions à or de contract with the definite articles le and les to give the following forms:
La and l' on the other hand do not contract after à and de. Note that these contractions also occur with two - and three- word prepositions ending with à or de (jusqu'à, près de, loin de, à côté de, etc.).
The prepositions à or de contract with the definite articles le and les to give the following forms: de + le = du de + les = des
à + le = au à + les = aux
La and l' on the other hand do not contract after à and de. Note that these contractions also occur with two - and three- word prepositions ending with à or de (jusqu'à, près de, loin de, à côté de, etc.).