你知道辅音 t 是如何变音的吗？

billzhao

The Flap

A flap occurs in three situations.

* G4 W' \0 W1 D  D( L  1. A flap occurs when a 't' comes between two vowels. The pronunciation of the 't' in these incidences sounds
9 A- ?$ l0 o8 b6 h      like a 'd' and is said very quickly.
                                    
* o. M. r+ z" i2 k; }         Listen to these sound changes. The first word is with proper enunciation, the second word is with the sound changes. Then the word is used in a sentence.
) s0 t" O! [9 U% L1 U# k% L                                     
9 l6 j) E$ y" r) Q6 [2 b8 T                 
. b  L# A7 K; c4 z  y+ U) J  water becomes wader
  Do you need some water?
                
  letter becomes ledder
0 i# O) y8 c1 L/ L* _  _0 }  The letter was in the mailbox.
                
/ b. h, L: ?! m! e; ]: L5 D- a! l3 N  bottle becomes boddle
  The bottle broke when it hit the floor.
                
* g: V; P9 Z% f+ v8 q6 x  butter becomes budder
  The butter melted in the sun.
                                    
  2. Flaps also occur when a 'd' comes between two vowels. The 'd' is still pronounced with a d sound, but it is
      said very quickly. In the normal pronunciation of the d sound the tip of the tongue is placed on the tooth
      ridge (the area where the top front teeth meet the top of the mouth) before the expiration of air to produce
+ [/ O4 i/ c* U. H; N, m      the sound. With a flap, the tip of the tongue barely touches the tooth ridge and the 'd' sound is made very
      quickly.   
                                    
        Listen to these sound changes. The first word is with proper enunciation, the second word is with the sound changes. Then the word is used in a sentence.
                                    
                   medical        She is a medical student.
                   sediment            
The sediment on the river bottom is course sand.
& U, B% r3 w8 |% z+ W
( W" @  K  w7 C' ~                    cadence           
; l, H* w5 V/ z4 A" }  U0 t8 Y6 Q9 uDrums keep the cadence in a marching band.
0 [4 ]) n* r; Z8 e- b+ \
                   cider         This apple cider is great.
                   spider        A spider has eight legs.
                                    
  3. The third flap occurs when with linking of the consonant final letter of one word and the vowel letter of the
5 o: @7 j! T' Y) L, r9 e, |& D       next. (see section on linking)
. b* j! p" d, c. a2 n                   
/ V- o8 i( \6 R0 O8 Z/ @. p         Listen to these sound changes. The first phrase is with proper enunciation, the second phrase is with the sound changes. Then the word is used in a sentence.
* i. R- @5 [# r. _* f- l- h                   
. s6 c; j( |& x3 E/ B3 Y            'right away'  becomes righ(d) da  way
          I'll get your bags right away sir.
! s& ~0 A  }7 J" w2 d
% s4 T, O" V9 o, ?/ |
                  
+ n3 H9 {7 f4 Z! _/ U4 @9 v            'what if' becomes whad dif
          What if we go to Paris for vacation?


                  
  W% d7 a) ]- P, c2 g# z             'might I' becomes migh(d) di         
3 z' k$ @% j- B8 c, \( b           Might I suggest a new tie?
. U  p% W  y, l0 U! F
1 K6 [* a8 Q/ _  [% j( t8 q5 o+ z
/ ]4 Q0 i& t+ {% ^$ ?                   
2 s/ R: n" V. m& R- w        
Note: The flap does not occur in some words (what, that) if they are spoken alone, without other words to
! z' G- t4 e8 H8 }) x  V$ c% Y          link to.

billzhao

The Glottal Stop
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When a 't' is followed by a vowel + n syllable  (eaten), the 't' sound is replace with a glottal stop, which is a complete closing of the vocal cords for a short moment. A glottal stop sound can be heard in the pronunciation of the negative uh uh.
5 P& C5 ]3 [* a% R# s" S
                           
$ f* Q5 ?. y( L# O/ h- m         Listen to these sound changes. The first word is with proper enunciation, the second word is with the sound changes. Then the word is used in a sentence.
* i( F  O# s  n: B                            
9 L# o  b3 A1 N6 t        
    'eaten' becomes ea'n  
1 ?# N0 k3 M! k0 r  {% y7 j  |   Have you eaten yet?
2 v% }5 i' M& @2 u! V  B        
    'satin' becomes sa'n  
   Satin sheets are nice to sleep on.
       
    'sentence' becomes se'ence
   This sentence makes no sense.
       
# w6 l. B6 K3 Q  z# ?" F8 q0 F/ N/ I    'mountian' becomes moun'n   
   I'm not much of a mountain climber.
6 j1 s5 V& f' e$ U  s) r        
    'getting' become ge'n        
   I'm getting to old for this.
       
: p, K' W" Z' J- d% s    'button' becomes but'n   
* ]4 g1 P$ ^- i9 [/ j" o$ Y0 w   Sam lost a button on his shirt.

billzhao

Can and Can't
5 `( ^1 r7 Q6 q3 [, O: K

In an affirmative 'can', the can is pronounced as 'kn'. The modal verb 'can' in the sentence is unstressed; the main verb is stressed.
& w% B9 Q4 @" n; _+ U                                              
   Listen to these sound changes. The first phrase is with proper enunciation, the second phrase is with the sound changes.
* F3 _$ M; p2 D( c   Then the word is used in a sentence.
                                             
* c* {6 T& n* ]5 @) k        
   'We can swim' becomes we kn swim  
   We can swim in the lake.
- B( J. e; z  e( A5 [

* l. w* w- Z4 K) Z+ \6 L/ f        
   'I can cook' becomes I kn cook.
   I can cook pizza.
( ~# p! {% t2 Q& N& t
- @0 D' u. C4 r( p& ]2 O
( `; A1 |) a6 G1 U  y5 J& V        
/ t; F2 [8 i5 t: a' n- r% h8 K, Y   'She can read' becomes she kn read  
/ m1 {6 Y2 x! T$ V% I4 ?1 L% \   She can read Italian and Russian.
  h/ ~; N) O) [4 d2 \0 T
6 V0 N8 Q; @2 r) F: D
) E0 `$ a5 r  w& w- k        
1 g- t! z. q- q0 r) }' Z   'They can ride' becomes they kn ride.
   They can ride on the roller coaster.
7 C  X, |& P- {: g, ?4 M+ }
                                             
  r" t6 n& }. i, m8 rIn the negative, both the modal (can't) and the main verb are stressed. However the 't' in can't is dropped and replaced with a glottal stop if the next sound is a consonant.
                                             
5 ?, p, K* O5 `' Z. d0 e& |: h   Listen to these sound changes. The first sentence is with can, the second with can't. Note that both the modal and main
& k# ^- G8 u  |, u; F/ O   verbs are stressed in the negative sentence.
% w4 N  p. E8 N  @" }                                              
       
  'We can't go' becomes
   We KAN' GO.  
$ w% o; h4 R: r2 Y2 s' Z' a
We can go to the movies.
We can't go to the movies.
3 I/ a! |# m& f: S* B
: d, o  Q' @$ ]  i5 ~' f# H        
  'Larry can't speak' becomes
   Larry KAN' SPEAK.

( s3 I7 Z+ @8 C% k  t2 R4 s( GLarry can speak French.
Larry can't speak French.
. M. `7 q; L: J. _  d! b
       
  'She can't do it' becomes
3 @) a( {4 g7 J$ w( g. r   She KAN' DO it   

She can do it.
She can't do it.
3 `  i5 W- r( x5 g* @: f9 T
$ h/ q9 l) F0 f        
  'Some people can't sing' becomes
, ]1 M* q" h! l2 V7 d0 v   Some people KAN' SING
% \  c0 v0 D% R: f0 a; KSome people can sing.
/ k8 p  |. I; P+ ~8 g5 ~; G' _: vSome people can't sing.

                                             
If the next sound after 'can't' is a vowel, a flap occurs as in 'She can't  ignore it'. (... can't  tig-nore...)
* G! L5 E' w; l1 M0 ?' Y7 e                                              
   Listen to these sound changes. The first phrase is with proper enunciation, the second phrase is with the sound changes.
; L+ M% b- x( I   Then the word is used in a sentence.
                                             
' h! a: i/ y+ _+ W( u        
   'can't attend' becomes can't  attend. (... cand da-ttend)
/ g4 K+ b, t5 f- a- ~+ k) U   We can't attend the concert.
       
   'can't invite' becomes can't  invite  (... cand din-vite...)
& o' \2 f" g4 K   Wally can't invite her to the party.
; ]3 ~8 I* ~* ^3 E1 g$ ~        
   'can't answer'  becomes can't  answer (.. .cand dan-swer)
   He can't answer the question.
$ d8 ~' j6 c3 k0 T3 U$ E2 x3 o
: {% n& j( U, Q5 y9 ?& J        
  y& [: \: a1 R7 d0 Y. w* d   'can't understand' becomes can't  understand (... cand dun-der-stand.. )
   I can't understand what you are saying.

billzhao

Negative Contractions

Many times a native speaker does not pronounce the final 't' in a negative contraction (can not= can't, do not =don't, have not= haven't). The pronunciation is replaced by a glottal stop. (see above)

/ o- u5 Z2 [5 z! _5 h                   
: g- j3 \! k8 d% p     Listen to these sound changes. The first phrase is with proper enunciation, the second phrase is with the sound
     changes. Then the word is used in a sentence.
                          
4 m6 G0 n' c0 N) |9 t        
& O1 C, i; W, E, }& k    'wouldn't'  becomes wouldn'      
" t; o0 x: s  j+ @: p   Why wouldn't you go to the dance with me?
       
   
. J  Z/ b: d  X& @$ i
       
    'couldn't' becomes couldn'
    I couldn't do it because I was sick.
       
) N3 c; V8 u; t# E   
" R6 p) ~$ m7 J" K( g
       
    'shouldn't' becomes should'n         
1 D) s6 a7 I# W- h$ A9 l   He shouldn't have eaten the apple.
       
   

/ W5 @' i( C5 M/ x        
    'doesn't' becomes doesn'
   Larry doesn't study hard enough.
. X: _" e$ c% x3 Q/ o
% E" J7 G, X& X1 m3 K