These contractions are not used where part of the letters comprising them fall into a base or root word and the remainder into a suffix. Thus, the sign for ed is not used in freedom or boredom.
Use caution when transcribing words that end in ry and ery. When the suffix ry is added to words such as image, rifle, and savage, creating imagery (im/age/ry), riflery (ri/fle/ry), and savagery (sav/age/ry), the er contraction cannot be used. However, when ry is added to slave and bake to create slavery (slav/er/y) and bakery (bak/er/y), the er contraction is used because all the letters of the contraction fall within the same syllable—a rule that takes precedence over the suffix rule.