cook
The French word 'cuisinier' is used to refer to either a professional cook, or anyone who's cooking. It could be used in contexts like: 'Je suis le cuisinier' which translates as 'I am the cook'. The verb 'to cook' is 'cuisiner'.
The cook is preparing dinner.
In the phrase, 'Le cuisinier prépare le dîner', 'Le cuisinier' means 'The cook' which is the subject of the sentence. 'Prépare' translates to 'is preparing' and is the verb, while 'le dîner' means 'the dinner' which is the object.
I want to be a cook when I grow up.
In this sentence, 'Je veux être cuisinier lorsque je grandirai', 'Je veux être' means 'I want to be', 'cuisinier' translates to 'a cook', and 'lorsque je grandirai' means 'when I grow up', expressing a future desire or objective.
He works hard to become a good cook.
In the phrase, 'Il travaille dur pour devenir un bon cuisinier', 'Il travaille dur pour devenir' translates to 'He works hard to become'. 'Un bon cuisinier' simply means 'a good cook'. This sentence speaks about someone's effort to achieve a goal.