"Descendre de" rule

Question

"Descendre de" ruleThis may have a simple answer, but if 'de' becomes du or des when followed by le or les, why would the correct response on the quiz be: Elle descend de l'avion rather than Elle descend du l'avion?

Accepted Answer

Bonjour Robyn,
To illustrate Chris's excellent answer, here are a few more examples:
le avion -> l'avion  - see link: le - la - l'   
descendre de l'avion -> masculine / word starts with a vowel
descendre du train -> masculine / word starts with a consonant
arriver de l'hopital -> masculine / word starts with the letter h
I hope this is helpful.
Bonne journée !

Answer

Descendre + de + le + avion. In this case the article could, theoretically, contract with the preceding de or the noun that follows, resulting in either descendre du avion or descendre de l'avion. The first one is wrong (it is also difficult to pronounce for French tongues due to the clashing vowels). The second one is correct.