Ethiopic is a Semitic language.
Buy a different book about Ge'ez.
Joseph Biddulph Guide to Ge'ez A kind of preliminary exercise in the study of Ethiopia's old liturgical tongue, the Semitic “Hebrew of Africa”, with self-help notes on the script, texts and pages of vocabulary to transcribe and examine. Partly handwritten to accommodate Ethiopic script. (It is hoped that these notes may be replaced or supplemented at a later date with a fuller treatment of this subject). 20 pages. U.K. £ 2.50. ISBN 0-948565-14-4
Lambdin, Thomas Intro to Classical Ethiopic 1978 scholar's press $44.95