Articulation of D and T

The letter D is either spoken in words or it remains silent. 

Words like Dad, Dog, Date, Depend etc carry the natural articulatory sound of D

Whereas D is silent in words  when it comes before or after N Handkerchief, Handsome, Wednesday etc.

D with G combined takes sound of J and D is not pronounced in words like Adjudge, Acknowledge, badge, sledge etc.

Like D, T is either pronounced in words like tattoo, take, two etc or it remains silent in words like fasten, listen etc

T is silent when  F, R, S comes before it. The following are the words which follow this rule

 Apostle, Bristle, Bustle, Castle, Christmas, Fasten, Glisten, Hasten, Moisten, Nestle, Often, Rustle, Soften, Thistle, Whistle, wrestle, Mortgage.

But T is articulated when it is the end letter in word as Fast, Last, East, etc.

When T is combined with CH, it remains silent because TCH is spoken tʃ (च).. I have already discussed it in detail in my previous blog.

When T comes with H it takes sound of (θ/थ) example words

Think, Bath, Third etc

T with H also gives the sound of (ð/ द) in words like this, that, these, those, then, there, thou, thy etc.

Common Words with the as (θ/थ) sound

Initial pronunciation of θ/थ

thanks - theaterAmE - theatreBrE - theme - theory - therapy - thick - thin - thing - think - thirteen - thirst - thirty - thorough - thought - thousand - threat - three - threw - throat - through - throw - thumb - Thursday

Final pronunciation of( θ/थ)

bath - beneath - birth - both - breath - death - depth - earth - faith - forth - growth - health - length - mathAmE - month - mouth - north - path - south - strength - teeth - tooth - truth - wealth - worth - youth

Middle pronunciation of (θ/थ)

anything - everything - nothing - something

athlete - author - ethnic - healthy - hypothesis  - mathematics - mathsBrE - method - monthly - strengthen - wealthy

Irregular plurals of words ending in θ/थ, as /ðz/

baths - mouths - paths - youths

Several plurals of words ending in θ/थ are pronounced as /ðz/ and also as /θs/

oaths - truths - wreaths

Common words with (ð/ द ) sound

With initial ð/ द

Grammar words: than - that - the - their - them - then - there - these - they - this - those - though - thus

mid-position ð/ द:

Grammar words: although - another - either - neither - other - rather - together - whether - within /wɪðˈɪn, wɪθˈɪnAmE/ - without /wɪˈðaʊt, wɪθˈaʊtAmE/

Content words: bother - brother - clothing - father - farther - feather - further - gather - leather - mother - northern - rhythm - southern /ˈsʌðərn/ - weather

With final ð/ द:

Grammar word: with /wɪð/ or /wɪθ/

Content words: breathe - smooth

Less common words

/ð/ in mid-position : heathen, heather, worthy

With final /ð/: bathe, booth /buːð,BrE buːθAmE/, clothe, loathe, soothe, teethe

Irregular plurals

Some words ending in /θ/ have a plural ending in /ðz/baths - mouths - paths - youths