7.7 Preserving the Usual Form of the Base Word [X.34.b(1)]

Be alert to base or root words that have more than one prefix. When words such as disturb, distinguish, or distinct take on a second prefix, as in undisturbed, indistinguishable, and indistinct, the dis is no longer the first syllable of the word and cannot be contracted. And, to ensure easy recognition of the word, the st is not contracted either. Example:

distinct indistinct

The same applies to ingenuous, where the ing contraction cannot be used because the letters occur at the beginning of the word. When the prefix dis is added to create disingenuous the ing contraction is still not used. This preserves the original form of the base word and ensures proper pronunciation. Example:

ingenuous disingenuous