Choose all the sentences which are grammatically correct.

• I'm more patient than my elder sister.
• Today isn't as warmer as it was yesterday.
• She's the most pretty girl I've ever known.
• Yesterday he started feeling more bad.
• I've got a headache. Be quieter, please.
• Kate isn't as hard-working as her best friend Jane.
• You shouldn't stop practising English grammar. The more you practise, the fastest you learn it.
• Be active at the lessons, please.