The study investigates adult Hebrew readers' perception of words containing the grapheme[Hebrew] in different orthographic and morphological contexts. In the first experiment, 38 third-year education students were asked to make lexical decisions regarding 24 pointed words (presented with vowel marks) in a sentential context in two conditions--with and without the grapheme [Hebrew] standing for the vowels "o" and "u". All words shared the same syllabic structure but had different morphological structures (linear and non-linear). Half of the words had [Hebrew] which obligatorily occurs in all types of Hebrew script, while half of them had [Hebrew] which is deleted in pointed script. Response latencies and accuracy were measured. In the second experiment, the same procedure was repeated using the same 24 words without pointing marks.The addition of [Hebrew] was found to facilitate correct decision on task words. We also found that both orthographic and morphological contexts affected the representation of "o" and "u" by [Hebrew]. We identified a category of Hebrew words where the status of [Hebrew] is particularly unstable. The study supports a Root-based view of Hebrew spelling and has implications for the interface of orthographic, phonological and morphological factors in the representation of written language. It also supports a reading/spelling processing model,which claims that internal orthographic representations of words are increasingly strengthened with each exposure during reading, but not all graphemes are strengthened equally. The general implication is that the ambiguities that exist in the relationships between orthography, phonology and morphology underlie spelling knowledge.