Pronunciation of Some Really Tricky Words. There are two words, can, and the negative contraction, can't, that seem to cause more trouble than any others. People don't usually pronounce these words clearly. So if someone says, we can help you. Did they say can or can't? Here are some clues for telling the difference between can and can't. Can is usually unstressed, and it sounds like /kən/, with a reduced vowel. We can help you. When can you help me? Can't is usually stressed. It sounds like /kaent/ with a clear sound. We may not be able to hear the final [SOUND]. We can't help you. Why can't you help me? But when can is alone, with no verb after it, it's stressed. Can you help me? Can is not stressed. Yes, I can. Can is stressed. There's no verb after it. Now, practice saying these sentences with can and can't. Notice which words are stressed. Eagles can fly, but penguins can't. Can ostriches fly? No, I don't think they can. Eagles can fly, but they can't live in Antarctica. Can't you tell me more about birds? No, I can't. Another tricky group of words is numbers ending in -teen and -ty. These are often very hard to tell apart, even for native speakers. Numbers like 14 and 40, 15 and 50, 16 and 60. Sound very similar. So how can we tell these numbers apart? If you look at the spelling of these words, it seems like it should be easy. Fourteen has an extra sound at the end, [SOUND]. Forty doesn't. But people don't usually pronounce that last sound very clearly. And sometimes, it gets blended into the words after it. Like when we say, 14 notes, or 40 notes. The [SOUND] doesn't actually help much. There are two important differences that you can hear between these numbers. The first difference is stress. Teen words are usually stressed on the second syllable. T words are always stressed on the first syllable. We say fourteen and forty. Say these numbers and notice where the stress is. Fourteen, forty. 15, 50. 16, 60. 17, 70. 18, 80. 19, 90. But sometimes the stress in -teen numbers changes. When we count, we usually stress the first syllable of each number. Thirteen, fourteen, fifteen, sixteen, seventeen. And when there's a noun after the number, we also usually stress the first syllable of the number and the noun that comes after it too. Fourteen children. Fifteen years. Sixteen books. Seventeen dollars. Another difference is the sound of [SOUND] that we hear. When we see the -teen numbers, like fourteen, we hear a clear, puffy [SOUND] sound. It's voiceless. Fourteen. When we say the -ty numbers, like forty, we hear a sound that's more like a [SOUND]. It's voiced. Forty. Now, say this numbers. Fourteen, forty. Fifteen, fifty. Sixteen, sixty. Seventeen, seventy. Eighteen, eighty. Now, practice saying these sentences with numbers. How many chairs do we need? We need sixteen. We need sixteen chairs for the meeting. How old is your grandmother? She's eighty. My grandfather is eighty years old, too. My aunt was born in nineteen seventy. This book costs $30.15. How many people will come to the meeting at 2:40? Fourteen. Keep practicing these tricky words, can and can't. And numbers with -teen and -ty, so that you can say them easily and clearly.