1
The day I knew her, I realised she was the perfect woman.
The day I met her, I realised she was the perfect woman.
Use meet when you see and speak to someone for the first time: ‘I met Anna at a party.’
Use know when you are already familiar with someone: ‘I’ve known Anna for ten years.’
2
They are still knowing each other, but they seem to be in love.
They are still getting to know each other, but they seem to be in love.
Use get to know someone when you spend time with someone and gradually learn more about them: ‘We are still getting to know each other.’
Use know someone when you are already familiar with them: ‘I know her very well.’
3
I have been knowing him for a long time.
I have known him for a long time.
Know is a stative verb, so we do not normally use it in continuous tenses. Use I have known, not I have been knowing.
The same rule applies to verbs such as believe, want and need.
4
Please read our brochure if you want to know the different activities we offer.
Please read our brochure if you want to know about the different activities we offer.
Use know someone when you have met them and are familiar with them: ‘I know Maria. We work together.’
Use know about someone when you have information about them but may not have met them: ‘I know about Maria, but I have never met her.’
We also use know about something when we have information about a subject: ‘I want to know about the activities you offer.’