English is the second most frequently spoken language in the world and has the largest vocabulary of any language. Half of all business deals are conducted in English. Two thirds of all scientific papers are written in English. Over 70% of all mail is written and addressed in English. Most international tourism and aviation is conducted in English.

Isn't it unfortunate that many people find English difficult to spell?
To understand why this is so, it helps to look at its history. The original inhabitants of Britain spoke a Celtic language but over the centuries, Britain has been invaded many times. Its conquerors always left some of their language behind them. During the 5th Century A.D., the Angles, Saxons and Jutes invaded and pushed the native Celtic speakers to the edges of the island, in to Wales, Cornwall and Scotland. Cornish died out in the 18th century but Welsh, Scottish and Irish Gaelic are still spoken. Their Germanic language was called Englisc from which we get English. Christian missionaries introduced the Latin alphabet that we still use today, from Southern Europe via Ireland.

In 1066 the Normans, from France, conquered Britain. French became the language of the court and the aristocracy, and Latin the language of the church and the law. This increased the English vocabulary. Many words in English have a" French" and a "Germanic" equivalent, e.g. stomach, belly. The Germanic form of plurals (house, housen; shoe, shoen) was eventually displaced by the French method of making plurals by adding an "s" (houses; shoes). A few words have retained their Germanic plurals: men, oxen, children.

King Henry IV, born in 1399, was the first king of England since the Norman Conquest whose mother tongue was English. By the end of this period, the dialect of London had become what we now call Middle English, Chaucer's language. At this time spelling varied throughout the country, depending on the local pronunciation, so we can often tell where old documents were written by their spelling.

When Caxton brought the printing press to England in 1476, books became cheaper and started to be published in English, rather than Latin. This brought standardization to English but although the spelling and grammar of modern English became fixed around the 16th Century and the first English dictionary was published in 1604 the language has continued to change. Through contact with many peoples from around the world, numerous words have entered the language.

The Industrial Revolution and the rise of the technological society created a need for new words to describe things and ideas that had not previously existed. Words like protein and vaccine were often taken from Latin and Greek roots. Then there was the British Empire. At its height, Britain ruled one quarter of the earth's surface, and English adopted many foreign words. Hindi, and the other languages of the Indian subcontinent, provided many words, such as pundit, shampoo, pyjamas, jodhpurs. Besides the vast contributions of French and Latin and Greek, virtually every language on Earth has contributed to the development of English, from Finnish (sauna) and Japanese (tycoon).

All these contributions and additions have mixed to make a very rich language soup, allowing us to express ourselves very well. When you spell an English word it probably isn't English at all, that's why it doesn't follow the rules. Very often, English has accepted the new words with their original spellings, but didn't adopt the original pronunciations, or pronunciations were changed by common usage, but the original spellings were never changed to match. We also know that English is pronounced in many different ways. Even people from different parts of Britain use different pronunciations, not to mention Americans, South Africans, New Zealanders, Australians, etc. So how can we really reach an agreement as to how things should be spelt in the 21st century?

You may well say, "How can I figure out how to spell the words in this crazy language?" We can invent mnemonics to help us remember the correct spelling of many words. For example: Hear contains the word "ear", "envelope" helps us remember that "stationery" with an "e" refers to office supplies, so "stationary" with an "a" must refer to something that is not moving! Then there's RAVEN _ Remember Affect Verb Effect Noun _ to remember when to use "affect" vs "effect". Sometimes using exaggerated pronunciation helps, such as exisTENCE or depenDENT. Or you can write lists of definitions for words that have the same sounds but are spelled differently, colonel _ kernel, berry _ bury, seen _ scene. Then there are words that contain letters that have nothing to do with the way they are pronounced, but when you write the words, you MUST include them, e.g. knife, plumber, iron, listen, castle. Most spelling rules usually have lists of exceptions that must be remembered.

The reasons for the ridiculous English spelling don't really matter because English is what it is; it has been this way for a long time. If you want to learn to speak and write it, you must learn it as it is and not how it should be. Spelling rules in English can be almost as much of a problem as spelling itself. So you can remember the rules and learn the 'tricks'; but you are left with this basic technique.

Read the article again:
Find these examples of the present perfect verb form

Which verb form is used with these expressions?
During the 5th century
In the 18th century
In 1066
At this time
In 1476
Around the 16th century
In 1604
At the height of the British Empire
Of course it's the past simple, as they all refer to events that are past and completed.