spare
The French word 'de rechange' is used to describe something that is kept as a replacement or backup, similar to the English word 'spare'. For example, you might have a 'roue de rechange' (spare tire) in your car in case you get a flat tire.
We need a spare tire.
In this sentence, 'de rechange' is used to describe an extra item kept in case another item becomes unusable. The phrase 'un pneu de rechange' means a spare tire in English. It is common to keep a spare tire in a vehicle in case of a flat tire.
I am using my spare phone.
Here, 'de rechange' indicates that the speaker is using an alternative or substitute phone. It's likely that their primary phone is broken or lost, so they're utilising a spare one instead. The French phrase 'mon téléphone de rechange' translates to 'my spare phone' in English.
She has spare glasses.
In this example, the term 'de rechange' is used to talk about additional items a person has. 'Des lunettes de rechange' implies that she has another set of glasses besides her regular ones, possibly in case the regular ones are lost or broken. So, it translates to 'spare glasses' in English.