alternative
In French, the word 'alternative' is used just like in English to describe a choice between two or more possibilities. It is a noun, and can be used in the same contexts as its English counterpart. For example, 'Il n'y a pas d'alternative' means 'There is no alternative'.
We must look for an alternative.
This sentence is in the imperative mood, commonly used for giving orders or making requests. 'Nous devons' is a way of expressing obligation or necessity.
This is an interesting alternative.
This sentence uses 'C'est' to make a definitive statement about something, in this case, 'an interesting alternative'.
The alternative is not clear.
This sentence is in the negative form, expressed using 'n'est pas' to deny the clarity of the 'alternative'.