Learn French: Isolé dans ce désert aride, le chameau allait mourir. - Isolated in this arid desert, the camel was going to die.

Isolé is a past participle used here as a detached adjective. In French, placing this phrase at the beginning of the sentence implies a cause-and-effect relationship without having to use a conjunction like parce que (because). It essentially translates the feeling of 'Because it was isolated in this arid desert, the camel was going to die.'

How do we determine the gender and number of Isolé in this structure?

A detached phrase at the start of a sentence must logically describe the subject of the main clause that follows it. Here, Isolé takes the masculine singular form to agree perfectly with le chameau. If the sentence were about a female animal like la souris (the mouse), it would be spelled Isolée.

Why is the verb allait in the imperfect tense here?

allait mourir is the past version of the near future construction (aller + infinitive). While il va mourir means 'he is going to die', putting aller into the imperfect tense (il allait) changes it to 'he was going to die'. It describes an action that was imminent at that specific background moment in the past, which is exactly what the imperfect tense is used for.

Could we place the adjective before the noun and say ce aride désert?

No, aride must follow the noun. In French, most adjectives that describe a literal physical characteristic, such as dryness, color, or shape, are placed after the noun. Only a specific list of common adjectives (often remembered by the acronym BANGS for Beauty, Age, Number, Goodness, and Size) typically come before the noun.