Jawaharlal Nehru often remarked that English is one of the most un-scientific languages! As opposed the Indian languages like Sanskrit, Hindi, Bengali or Marathi, where the grammar rules are the same that one studies in school and what the last generation studied in their school, English grammar changes quite rapidly and what you learnt in school might be rendered redundant or labelled stuffy and pedantic in a few years.
People from vernacular, non-English medium background often find themselves at a disadvantage in spoken English as compared to those from an English medium or convent school background. This article is an attempt to help such people avoid simple mistakes and speak more confidently by keeping few rules in mind.

Points to remember:

1. Always speak in short sentences. Instead of trying to join two or more sentences by using and, but, although etc, it is better to speak in short and simple sentences.
2. Do not think in your mother tongue and then translate your thoughts into English. Try to structure your thoughts in English before speaking them aloud. This is where your English medium educated colleague has an edge over you.
3. Avoid using 'back' with words like 'revert' or 'return'. Return itself means bring back or come back. So return back is wrong. Correct usage is simply: Please return the library book or he'll return home after six. Similarly, Revert if in doubt is correct as opposed to revert back to my mail.
4. Take care of the verb and its object. A verb is the word describing action (ex. Do, is, have etc) and object is the noun/ pronoun whose action it describes. Points that need to be taken care of are the tense of the verb and its singularity/ plurality. Refer to this table when in doubt. If we speak in simple present tense, we'll just take care of the singularity and plurality of the verb. (We'll take up tenses in the next article.)

First person, singular (I): am, have, do, run/ talk/ read. (I am. I do. I run.)
First person, plural (We): are, have, do, run/ talk/ read. (We are. We do. We run.)
Second person (You): are, have, do, run/ talk/ read. (You are. You do. You run)
Third person, singular (he/ she/ it): is, has, does, runs/ talks/ reads. (He is. She does. It runs.)
Third person, plural (they): are, have, do, run/ talk/ read. (They are. They do. They run)

5. Keep few regularly used prepositions in mind. Prepositions are words that describe the position and relationship of on object with other nouns or pronouns in the sentence. Example, I went to the office. Here 'to' is the preposition. Prepositions describe the relationships including time, direction, place, manner and amount. Following are commonly used prepositions:
*Prepositions are in capitals.

Set UP an office/ camp.
Take UP an offer.
Investing IN shares.
Interested IN Computer Science.
Working WITH a company (working in association with).
Working FOR a company (as an employee of).
Listen TO your teacher.
Know ABOUT the job offer you got.
Let's make a deal WITH them.
Be delighted WITH your child's progress.

There are few words and phrases with which prepositions are NOT used.

Home.
I went home.
This morning/ afternoon/ evening
Let's meet this afternoon.
Every week.
I go to the theatre every week.
Next/ last year/week/ month/ Tuesday.
We'll return next year.

6. Read magazines and newspapers regularly and make it a point to read aloud for 10 minutes every day.
7. Watch English news regularly and notice how sentences are structured.
8. Always keep a dictionary handy and refer to it.

These are the basics for error-free spoken English. See you soon with some more handy tips and rules.
Happy Speaking!