yea i would suggest dont use this word dear at all, as to me it seems quite gay.
apart from that, read books, articles, journals, newspapers etc. and you would be able to improve your english, to a great extent.
a tip from my side: When you come across a new word while reading or listening to a conversation, make sure to write it down with you, better create a word file for all the new words you come across. This way you would be able to remember the new words and search for them at a later stage and keep a track of them. Because if you dont try to use the new words you have learnt, chances are you may forget them.