(3) Go to our standard SWITCHBOARD lexicon and extract 20 words
    which can be represented as 10 valid English morphemes plus
    stems. Explain the relationship of these morphemes to syllables.

solution: 

morphemes: smaller meaning-bearing units i.e, minimal meaning-bearing
unit in a language.

The stem is the main morpheme of the word, supplying the main meaning;
while affixes - gives additional meanings of various kinds.

word                  stem         +    affixes	     => syllable for morpheme
Account         -->   Account
Account's       -->   Acoount      +    s
Accountability	-->   Account      +    ability
Accountable     -->   Account      +    able
Accounts        -->   Account	   +    s
Accountants     -->   Account      +    ant + s
Accountant's    -->   Account      +    ants 
Accounted       -->   Account	   +    ed

Custom		-->   Custom       
Accustom	-->   Custom	   +    Ac

Act		-->   Act	   
Actor		-->   Act	   +	or
Actors		-->   Act	   +	ors
Actress		-->   Act	   +	ress
Actor's		-->   Act	   +	or + s
Actresses	-->   Act	   +	ress + es
Acts		-->   Act	   +	s

ADD		-->   Add	   
Adder		-->   Add	   +	er	       => er sil
Addition	-->   Add	   +	ition	       => ih sh ih n sil
Additional	-->   Add	   +	ition + al     => ih sh ih n ax l sil
Additions	-->   Add	   +	ition + s      => ih sh ih n z sil
Additives	-->   Add	   +	itive + s      => ih k t ih v sil
Adds		-->   Add	   +	s              => z sp | z sil

Syllable is defined as basic unit of speech. Morpheme can be a
syllable like for example in adder, er is a morpheme as well as a
syllable.

reference 

1: section 3.1 - 3.3 of the text-book