If the phosphates are on different carbons, then it would be called a bis or tris compound. It is a difficult key. Notice the SEPARATE idea of Divide and Divorce. Prefixes are morphemes (specific groups of letters with particular semantic meaning) that … Navajo verbs with disjunct prefix di-. Twice, two, double. Some older examples derive from Greek words already containing the prefix, such as diphthong, a sound formed by the combination of two vowels in a single syllable (Greek diphthongos, from phthongos, voice or sound), or dilemma, a situation in which a difficult choice has to be made between two or more equally undesirable courses of action (Greek dilēmma, … Barton Reading. Origin of dis-1