Details
B /b/ usually a consistent sound (bat, bell)
can be silent in words such as comb, subtle, thumb
C /k/
can have a hard K sound when followed by an O or an A (cat)
can also be soft when followed by an E, I, or Y (face, circle, fancy)
D /d/ a consistent sound (dog, dirt)
F /f/ a consistent sound (fun, favourite)
G /g/ can have a hard sound (go, get)
can also be soft when followed by an E, I, or Y (orange, region, gym)
there are exceptions to this rule (girl)
can be silent when followed by an N (sign)
GH can form an F sound (laugh), or be silent (naughty), or can sound like
G (spaghetti)
H /h/ can be a consistent sound (home, hockey)
can be silent (honest)
is often combined with other letters to make consonant digraphs
J   a consistent sound (January, junk, Jennifer)
K /k/ a consistent sound (kite)
can be silent when paired with an N (knife)
L /l/ a consistent sound (look, lucky, lake)
often blends with other consonants
can also be silent (half)
M /m/ a consistent sound (moon, mighty)
N /n/ a consistent sound (nine, nice)
can also be silent (autumn, hymn)
P /p/ a consistent sound (puppy, penguin)
can be silent (psalm, receipt)
can sound like an F when combined with an H (photograph)
Q /kw/ almost always paired with a U (queen)
may sound like a K when the U is silent (liquor)