Free How to Learn a Foreign Language by Graham E. Fuller

Because that's the way English works. The third person form always has to have an “-s” ending. Furthermore, it's not correct without it. Sure, you could understand it without the “-s” on the end—“he go”. But that's not the way the language works. And it sounds like Tarzan.
    Actually there is a reason why most languages—even Old English—put endings on verbs to denote “person”. The point was that the actual verb—without the pronouns “I”, “you”, or “he” or whatever—could be used by itself. In Russian today you can use just the one word “ znayete ” and it's clear that you mean “you know” without actually using a second word “ vy ”meaning “you”. Before dismissing verb endings as “un-English” and impossible to master, take a look at Shakespeare or even at the Bible. You'll find lots of phrases like “thou knowest” and “whither goeth John.” These don't give us a problem there, so we shouldn't be bothered by verb endings in foreign languages. Our own language simplified itself many hundreds of years ago so it doesn't draw those distinctions anymore, except in the “he” “she” “it” form where it keeps the ancient “-s” ending.
    But then from the point of view of some other languages, English is fussy where they are not: In Chinese they say “one book, two book, many book”, while in English we have to put an “-s” on the end of each word to show it is plural: “one book”, but “two books, many books”. The Chinese asks, “Why do you need to put an “-s” on the end of the word when the words “two” and “many” already clearly indicate that there is more than one book anyway?” The Chinese would be right—from his point of view. But you have to remember that languages are never intrinsically logical. And each speaker of a language thinks the way that other people speak their language is illogical, complicated or unnecessary.
    Both Arabic and Hebrew have different words for “you” (to a man), and “you” (to a woman), in addition to a difference in verb ending. An English speaker would say, “That's completely unnecessary. One word “you” does perfectly well for both.” Who's right?
    The Turks have just one word for “he”, “she”, and “it”. They look at English and say, “Why do you have three different words for these things when one word does perfectly well for all of them?”. Japanese and Javanese (Indonesia) regularly distinguish between levels of politeness by the verb they use.
    The fact is, you can't really spend time arguing about such matters. That's just the way they are. But it is interesting to see how thought processes differ from language to language—and country to country. That's what languages are all about. And that's why languagestudy teaches us so much about foreign cultures, and about our own language as well. Things that we take for granted as “natural” turn out not to be natural at all, but simply the way that we do things.
KEY POINTS
    1. Grammar is the skeletal structure that links words together and gives them full meaning.
    2. Correct grammar is not so much designed to create elegant speech as it is to make clear what the relationship is among words. This is why we have to learn it.
    3. Each language makes its own sharp distinctions. You need to be ready to: a) learn new distinctions that we don't make in English, and b) ignore the distinctions we make in English that are not there in the foreign language.

CHAPTER ELEVEN
NO END TO ENDINGS (MORE UGH)
    A n the last chapter we talked about what grammar is, and how—even as small children—we can know it without having to study it. We saw that each person feels his own language says things the “natural” way. We also talked a little about word endings—especially on verbs. In this chapter we're going to take a longer look at endings: specifically at how some languages put different endings on nouns.
    One key difference between English