silent letters - 2

the letter g is silent when it occurs at the end of the word before 'n' or 'm'   (and remains silent before the -ed suffix)
e.g.
\ri-ˈzīn\       resign 
\ˈsīn\          sign
\ə-ˈsīn\        assign
\ˈrān\           reign   
\ˈfr-ən        foreign (also foreigner)

 

but it is pronounced in :
signature, resignation, assignation, ignore, pregnant
e.g. 
\ˈig-n(ə-)rənt\    ignorant

 

the letters 'ough' have a variety of pronunciations:

Full list of pronunciations

Pronunciation
Example
Comment
/ʌf/
tough, enough,
rhymes with 'stuff'
/ɒf/
cough, trough
rhymes with 'off'
/aʊ/
bough, plough
rhymes with cow
/oʊ/
though, dough
rhymes with 'go'
/ɔː/
thought, bought
past forms of verbs, rhymes with 'short'
/uː/
through,
rhymes with 'two'
/ə/
thorough, borough
Both pronounced /oʊ/ in American English
/ʌp/
hiccough
Variant spelling of "hiccup", though the latter form is recommended in both British and US
 
 
 
/ɒx/
lough
A lake; Irish analogue of Scots "loch"
 
'augh' is similar to the pronunciation of 'ough'  in the past forms of the verbs -  catch and teach - caught, taught  /ɔː/  - and in daughter
but can also be pronounced differently  as in
 /ɑːf/ as in "laughter

Listen to Lady Gaga singing "I like it rough" with lyrics