English Words

Base
and 
Stem
.
Schwa
The vowel represented by the symbol [e].
Semantic field
An area of meaning containing words with interlocking senses such that
normally you cannot understand one properly without understanding at
least some of the others, e.g. the kinship terms (father, mother, sister,
daughter, son, uncle, aunt, grandmother, grandfather, cousin etc.)
constitute a semantic field.
Spoonerism
A type of speech error where by accident (or sometimes by design, one
suspects) initial sounds in syllables of neighbouring words swap places,
e.g. 
The Lord is a shoving leopard to his flock
(Revd William Spooner).
Stem
Any form to which 
inflectional affixes
can be attached 
see also
Root
and 
Base.
Stop
A consonant made by closing the path of the airstream at the place where
the articulators meet so that air is not allowed to go through the centre
of the mouth past the obstruction, e.g. [p], [b].
Stress
The relative auditory prominence of a syllable.
Subject
The part of the sentence containing a noun phrase which precedes the
verb and agrees with the verb in number, e.g. ‘
Her daughter
is a
firefighter’ vs. ‘
Her daughters
are brilliant’. Typically, the rest of the
sentence (called the predicate) says something about the subject.
Suffix
An affix that goes after the stem e.g. 
-er
in 
tall
-
er see also
Affix
.
Suppletion
A case of morphological alternation where forms representing the root
morpheme bear no phonological resemblance to each other, e.g. 
good
~ 
better
.