RS: Modals are words like can, could, will, would, may, might, and must. The list goes on. And they can be tricky to learn.

AA: We get more of an introduction from English teacher Lida Baker in Los Angeles.

BAKER: The modals have descended from verbs but they don't have the same characteristics. For example, modals never take an 's' ending. So a verb, for example, you say 'I go,' 'you go,' 'he goes.' But with modals it would be 'I would,' 'you would,' 'he would.' There's no difference."RS: "Why are they so difficult to learn?"BAKER: "One of the reasons is that almost every modal can be used in more than one way. As an example, the modal 'can' can have the meaning of ability, like 'I can swim.' But it can also have kind of a predictive meaning, where you can something like 'it can rain later today.'"AA: "Now what about the word 'must.' Talk a little bit about 'must.'"BAKER: "'Must' is a very interesting word. We don't use 'must' a whole lot in the U-S. It's used a lot more in Britain. But we do use the quasi-modal 'have to' a lot in the United States, and we pronounce it as 'hafta,' as if it were one word. 'Must' and 'have to' have the same meaning. They have this meaning of obligation, like 'I can't go to the movies with you tonight because I have to do my homework.' Now something that's interesting about the words 'must' and 'have to' is, what's the opposite? Is it 'must not'?"AA: "Sure, 'you must not go."BAKER: "Aha -- wrong!"AA: "Oh."BAKER: "In fact, the opposite of 'must' isn't 'must not.' The opposite of must is 'don't have to,' because what we're talking about here is the sense of obligation. 'Must' and 'have to' mean you have to do something because you're obliged. What we're looking for is something that has the meaning of no obligation, and the way we do that in English is to say 'don't have to.' 'You don't have to do you homework now, you can do it later.' And by the way 'mustn鈥檛 is almost never said in U-S English."AA: "It's British."BAKER: "It's very British."AA: "Now here's an example, you walk into a room, you want to sit down, you want to ask the other person for permission, just to be courteous. What should you say?" Do you say 'may I' -- "BAKER: "'May I sit down.'"AA: "'May I sit down.'"RS: "Or 'can I sit down.'"BAKER: "Now, depending on the circumstances, you see. Because another function of modals is to express degrees of formality. So if you're in a bar, and it's noisy and it's very casual, you might say 'can I sit here.' You'll use 'can.' If you want to make it a little bit more formal, a little more polite, 'could I please sit here?' If you're in an elegant restaurant or something like that, or if you're speaking to someone who clearly is -- I don't want to say above you in status, that's a very un-American way of thinking."AA: "Someone in authority."BAKER" But someone who has more authority than you or is older than you, you might use 'may' because it's more formal, it's more polite, 'may I please sit here?'" So we use modals to express degrees of formality."RS: "So simply by listening and perhaps jotting down what you hear, or questioning when someone says something you don't understand that has a modal in it, and keeping a list of those in the context, might help you."BAKER: "That's one technique. Another technique is an eavesdropping technique where when you hear people talking, you kind of in your mind repeat what they've just said. So if you hear someone in a restaurant say 'could I please have some more coffee,' you sort of repeat that to yourself, 'could I please have some more coffee, could I please have some more coffee."AA: Lida Baker teaches at the American Language Center at the University of California at Los Angeles. She also writes textbooks for English learners, available through the McGraw-Hill Publishing Company.

RS: However, Lida Baker cannot reply to messages personally. So send your questions to VOA Wordmaster, Washington DC 20237 USA, or [email protected]. And, you can find our programs on the Web at voanews.com/wordmaster. With Avi Arditti, I'm Rosanne Skirble.

MUSIC: "Anything You Can Do, I Can Do Better"/Ethel Merman and Bruce Yarnell [Song from the play "Annie Get Your Gun"]