1. TENSES

2. 12 Basic Tenses: PAST
Past perfect continuous: : an action that happened before a certain time in the past, to show duration. For example: I had been going to school for a year when it was closed.
Past perfect: an action that happened before another event in the past. For example: I had washed the car before it rained.
Past continuous: an action that happened at a specific point in the past. For example: I was washing the car when it rained.
Past simple: an action that happened in the past. For example: I went to school.

3. 12 Basic Tenses: PRESENT
Present perfect continuous: an action still continuing from the past to the present. For example: I have been learning English for three years.
Present perfect: an action started in the past that has been completed in, or has relevance to, the present. For example: I have already studied the tenses today. 
Present continuous: an action occurring now. For example: I am studying.
Present simple: a general ongoing, regular or scheduled activity. For example: I take English classes every Monday.

4. 12 Basic Tenses: FUTURE
Future perfect continuous: an action at a certain point in the future, expressing duration. For example: I will have been studying English for three years this summer.
Future perfect: an action that finishes in the future, before or at the time of another future action. For example: I will have learned all the tenses by tomorrow.
Future continuous: an action occurring at a specific point in the future. For example: I will be fishing this time next week.
Future simple: an action to be completed in the future. For example: I will go to the cinema.

7. The type of writing you are doing will determine the tenses used that is most effective
RESEARCH REPORTS
LETTERS
JOURNALISM
PRESS RELEASE (PUBLIC RELATIONS)
ADVERTISING

8. Island in focus: Quake destroys three houses in N. Maluku
The Jakarta Post, Ternate | Archipelago | Fri, November , 3:28 PM
A 3.4 Richter-scale earthquake shook Jailolo, North Maluku, on Thursday, damaging three houses in the city.
“Residents went out of their houses in panic, afraid that buildings may collapse. Some residents of Bobanehena village were evacuated and moved to a hilly area due to fears of a tsunami,” the West Halmahera Disaster Mitigation Agency head Chalid Ismail said, as quoted by Antara news agency. However, no tsunami occurred after the quake.
Beside three damaged houses, Chalid said 10 other houses in the village were slightly cracked due to the earthquake and several subsequent aftershocks.
He said his agency had deployed officers to identify damage to the houses belonging to residents, Ansar Abdullah, Naser Peluh and Awaldom.

12. Tenses for promoting yourself or your product
What tenses should you use when writing a CV/cover letter/service history/describe product?
When you describe your history, or your experience, the initial temptation is to write in the past tense. These are events you finished: I completed a degree in Science; We produced an award-inning gyroscope. 
the past tense should really only be used in copy if you want to emphasise that something was completed – and you wanted it to stay complete:
My plans for banking reform prevented a stock-market crash.
I built a wall that kept the city’s wild dog community from escaping.
It is also useful if you want to emphasise duration:
I worked as a translator for fourteen years.

13. Tenses for promoting yourself or your product
But without wanting to put emphasis on the completion or the period of time, a present tense form is often more effective:
I have a degree in Science.
We have produced an award-winning gyroscope.
I work as a translator.
The choice of tenses here give the sentences current impact: they say you haven’t left your experience behind. The second example tells the reader the product is still available, and implies it is an ongoing success.

14. Tenses for promoting yourself or service: PRESENT PERFECT
The present perfect (have + past participle) says that this event, though having happened in the past, is still relevant now. It doesn’t have to tell you why it’s relevant, the tense on its own is a signal that the action is still important. Consider:
I went to the shop.
I have been to the shop.
The latter has more impact. It tells us the shopping trip could change our attitude to the current moment. It could change our life right now. Sentences promoting yourself or your service can differ in the same way:
I worked with the best accountants in London.
I have worked with the best accountants in London.
The latter tells us that you are still working, for a start, and implies that you these people you worked with in the past are still an option for the future. The simple past version is just a background detail, the present perfect gives possibilities looking forwards.

15. Tenses for promoting yourself or service: SIMPLE PRESENT
When you are writing to sell something, and you have an ongoing benefit or point of experience, the present simple is your best friend. It says that not only can you do something, but you are doing it. Consider the differences:
I worked with contacts across the globe. – You did so some time ago, not any more.
I have worked with contacts across the globe. – You did so in the past, and intend to continue doing so given the chance.
I work with contacts across the globe. – You have done so in the past and are doing so now, and will keep doing it now regardless of whether or not you win this client / customer / job.