Remember, your language and choice of words when expressing yourself make a big difference.
The English language is the accepted medium of communication and it's imperative that you develop a command over the language.
i. Proper diction and the appropriate use of words is important. Groom your language skills by reading more, watching English news channels and conversing with people who speak the language well. Writing down your thoughts also helps.
ii. Develop the right etiquette, manners and humility through your language by observing those you admire at work. Talk to people who know better and practise with their guidance. There are many professional courses today that offer this kind of training.
iii. In case vernacular languages are permitted, communicate in the language you are most comfortable with.
iv. Use simple, yet positive words.
v. Be polite; use words and phrases like Please; May I?; Very kind of you; Thank you; If you please; Pardon me and Excuse me.