The most widely spoken Semitic languages today are (numbers given are for native speakers only) Arabic (300 million), Amharic (22 million), Tigrinya (7 million), Hebrew (~5 million native/L1 speakers), Tigre (~1.05 million), Aramaic (575,000 to 1 million largely Assyrian fluent speakers) and Maltese (482,880 speakers).
Semitic languages occur in written form from a very early historical date, with East Semitic Akkadian and Eblaite texts (written in a script adapted from Sumerian cuneiform) appearing from the 30th century BCE and the 25th century BCE in Mesopotamia and the northern Levant respectively. The only earlier attested languages are Sumerian, Elamite (2800 BCE to 550 BCE) (both language isolates), Egyptian and unclassified Lullubi from 30th century BCE. However, most scripts used to write Semitic languages are abjads – a type of alphabetic script that omits some or all of the vowels, which is feasible for these languages because the consonants in the Semitic languages are the primary carriers of meaning.
Among them are the Ugaritic, Phoenician, Aramaic, Hebrew, Syriac, Arabic, and South Arabian alphabets. The Ge'ez script, used initially in Yemen, and later also for writing the Semitic languages of Ethiopia and Eritrea, is technically an abugida – a modified abjad in which vowels are notated using diacritic marks added to the consonants at all times, in contrast with other Semitic languages which indicate diacritics based on need or for introductory purposes. Maltese is the only Semitic language written in the Latin script and the only Semitic language to be an official language of the European Union.
The Semitic languages are notable for their nonconcatenative morphology. That is, word roots are not themselves syllables or words, but instead are isolated sets of consonants (usually three, making a so-called triliteral root). Words are composed out of roots not so much by adding prefixes or suffixes, but rather by filling in the vowels between the root consonants (although prefixes and suffixes are often added as well). For example, in Arabic, the root meaning "write" has the form k-t-b. From this root, words are formed by filling in the vowels and sometimes adding additional consonants, e.g. كتاب kitāb "book", كتب kutub "books", كاتب kātib "writer", كتّاب kuttāb "writers", كتب kataba "he wrote", يكتب yaktubu "he writes", etc.
The similarity of the Hebrew, Arabic and Aramaic languages was accepted by Jewish and Islamic scholars since medieval times. The languages were familiar to Western European scholars due to historical contact with neighbouring Near Eastern countries and through Biblical studies, and a comparative analysis of Hebrew, Arabic, and Aramaic was published in Latin in 1538 by Guillaume Postel. Almost two centuries later, Hiob Ludolf described the similarities between these three languages and the Ethiopian Semitic languages. However, neither scholar named this grouping as "Semitic".
The term "Semitic" was created by members of the Göttingen School of History, and specifically by August Ludwig von Schlözer (1781) and Johann Gottfried Eichhorn (1787) first coined the name "Semitic" in the late 18th century to designate the languages closely related to Arabic, Aramaic, and Hebrew. The choice of name was derived from Shem, one of the three sons of Noah in the genealogical accounts of the biblical Book of Genesis, or more precisely from the Koine Greek rendering of the name, Σήμ (Sēm). Eichhorn is credited with popularising the term, particularly via a 1795 article "Semitische Sprachen" (Semitic languages) in which he justified the terminology against criticism that Hebrew and Canaanite were the same language despite Canaan being "Hamitic" in the Table of Nations:
In the Mosaic Table of Nations, those names which are listed as Semites are purely names of tribes who speak the so-called Oriental languages and live in Southwest Asia. As far as we can trace the history of these very languages back in time, they have always been written with syllabograms or with alphabetic script (never with hieroglyphs or pictograms); and the legends about the invention of the syllabograms and alphabetic script go back to the Semites. In contrast, all so called Hamitic peoples originally used hieroglyphs, until they here and there, either through contact with the Semites, or through their settlement among them, became familiar with their syllabograms or alphabetic script, and partly adopted them. Viewed from this aspect too, with respect to the alphabet used, the name "Semitic languages" is completely appropriate.