Expressions: Indian vs British

There are some words or expressions typical of the British English, as spoken in London.  I do not claim to collate them all here but thought it might be good to identify some of these before I get so used to them that I do not notice the difference:

• 08.30 am: back in India it would be 'eight thirty', but here it is 'half eight'.
• 'pavement' here and in India we call the same as 'footpath'. But certainly in India there is hardly any place where we don't tread! 
• Most people here use the expression 'you know' quite too liberally.  Initially I was tempted at times to interject, "No, I don't!' Though redundant, it is very much part of any conversation or talk.  In India, I've come across people who use the word, 'no?' quite often in their talks. 
• A tall building housing many occupants is called a 'towerblock' here.  In India we'd call it plainly a building. 
• 'Headmaster' or 'Principal' in India would be the 'head teacher' here in the UK. 
• Everyone here is addressed by their first name.  No matter who or what he or she is, no matter who is addressing, everyone calls everyone by their first name.  At the university, the professors are addressed by their first name by the students.  Not once have I ever heard the word 'sir' or 'madam'.  Only when addressing someone officially will one use the prefix 'Mr' or 'Mrs', but then it is followed not by the first name but the surname.  The name of the head teacher is James Kibble.  For all, staff and friends, he is James.  For the students, he would be Mr Kibble.  But even that, only while at school.  Otherwise it is James!