It is true that Amharic, the official language of Ethiopia, is considered a Semitic language. It has, however, been significantly influenced/modified by Northeast African ("Cushitic") languages.
More precisely, Amharic is generally classified as a Semitic language, specifically a "South Semiitic" language, related to the languages of South Arabian tribes. More distant Semitic languages include Hebrew, Aramaic, Phoenician and Punic("Northwest Semitic"); the ancient dialects of the Assyrians and Babylonians [known now as "Akkadian"] ("East Semitic"). (The exact system is somewhat debated, including the best way to classify Arabic.)
http://en.wikipedia.org/wiki/Semitic_lan...
Amharic is related to the older, somewhat more purely Semitic language known as "(Classical) Ethiopic" or "Ge`ez", a language that is still used for liturgical purposes in the Ethiopic church. (The exact nature of the historical relationship of these languages is debated.)
Amharic also uses a modified form of the Ethiopic script, an interesting system of writing by syllables, created by modifying the the older Semitic alphabets. Older Semitic alphabets, such as those used by the Phoenicians and Hebrews did not generally mark vowel sounds; but the syllabary system of "abugida" of Ethiopic modifies each letter (all of which are consonants) to indicate the vowel following it.
As noted above, Amharic is not "pure" Semitic. Its grammar and vocabulary have been modified by interaction with neighboring African languages. The general explanation is that South Arabian tribes invaded the area and imposed their Semitic language on the native Ethiopians, but the original local languages reshaped it into a new language. (Amharic "deviates" from the Semitic languages much more than Classical Ethiopic.)
Amharic also plays an important part as the official language of a modern religious group known as Rastafarians who accepted former emperor of Ethiopia Haile Selassie I, the, as Jah, that is, God incarnate
http://en.wikipedia.org/wiki/Rastafari_M...

