you're
Follow the link to learn how to avoid confusing this word with 'your'
more information: your & you're
longest
Longest, largest, best and warmest are all superlative adjectives, something you can find out more about if you follow the link.
more information: superlative adjectives
came
Came is the past tense of the irregular verb come. Follow the link to find out more and to listen to examples.
more information: come
look after
To look after somone or something is to care for them and keep them in good condition.
Example: We need someone to look after the garden while we're on holidays.