双元音是两个元音的组合，发音的音长与长元音的长度相近。我们发双元音的时候，舌头从一个发音位置滑动至另一个发音位置。英语音标中共有8个双元音，被分为两种：集中双元音3个和合口双元音5个。集中双元音是以中元音[ə]（即舌中部发音）结尾的双元音，所以叫做集中双元音。
集中双元音(1) /ɪə/
发音要点
舌位由元音/ɪ/向元音/ə/滑动，不到/ə/音即告发音结束，舌位由高到低，牙床由半闭到半开，唇形由扁平到略大，成自然状态。
音标体验
发/ɪə/音的字母和字母组合ear,eer
ear: ear hear tear
eer: deer beer
根据发音规则，圈出每组中发/ɪə/的1个单词。
1. bear beer fair tail
2. noodles pair near come
3. horse hear tower air
4. ring king tear three
对话演练(Dialogues)
A:Hello,My dear,can you hear me?
B:I do,but not clearly.
A:Bring back some beer and a toy deer for Jill.
B:Ok,some pears and a Teddy bear.
A:Oh,dear.
Speak out
1)New Year's Day is near.
2)We're near the end of the year.
3)They cheered the hero when he appeared.
4)She's sincere,serious and a bit mysterious.
5)Is there a post office near here?
6)I want to be quite clear on this problem.
7)Things are clear and you don't have to fear.
集中双元音(2) /eə/
发音要点
先发前元音/e/,舌前部抬高，介于元音/e/和/æ/之间，倾向于/æ/的舌位，由/e/向/ə/滑动，不到/ə/音，发音即告结束；舌位由低到高，牙床由大于半开到略小于半开；唇形扁平到自然。
音标体验
发/eə/这个音的字母和字母组合air ear are
air: air hair chair pair
ear: pear bear wear
are: hare share
根据发音规则，圈出每组中发/eə/的1个音词
1.bear idea pineapple tail
2.noodles pair climb come
3.horse house tower air
4.ring king hare three
对话演练(Dialogues)
A:Let's go there,Cary.
B:No,I don't want to go there.
A:Why not,Cary?
B:I'm afraid of the bears on the stairs.
A:Well. They're all plastic bears full of air.
Speak out
1)Where there's will,there's a way.
2)I swear I'll never tell anyone.
3)She was not aware how deeply he loved her.
4)Why did you buy another pair of shoes?
集中双元音(2) /ʊə/
发音要点
/ʊə/的发音是由/ʊ/向/ə/滑动，不到/ə/音，发音即告结束；舌位由高到低，牙床由小到大，由半合到接近半开；唇形自然由圆形到扁平。
音标体验
发/ʊə/这个音的字母和字母组合oor,our,ure
oor: poor moor
our: tour tourist
ure: sure pure
根据发音规则，圈出每组中发/ʊə/的1个单词。
1. clear tourist pineapple tail
2. noodles pair climb fury
3. beard sure tower air
4. voice king pure engineer
对话演练(Dialogues)
A:Is this jewel from your boyfriend?
B:Sure. He wants me to marry him.
Speak out
1)He's from a very poor family.
2)We were unsure about who was to blame.
3)I'm sure that's pure gold.
4)The tourist was curious to know the story behind the mural.