Since Semitic languages prefer not to begin words with consonant clusters, in words where that occurrence would be likely it is common for an aleph to appear with a short vowel (thus, for example, what would be tsbac becomes ’ets-bac at the beginning of the word. See Moscati, p. 59, §9.14. Some very early Akkadian texts show a tendency to put an initial i- before words that otherwise would not be expected to have a prosthetic aleph.