The dagesh does two things: It marks a doubled letter, and it differentiates a stop from a fricative.
By DR. JOEL M. HOFFMAN
'What's the deal with the dot?" is a question I get a lot. The query refers to the dagesh, which for months I've been promising to explain. So here's Part 1.
First off, the dagesh does two things: It marks a doubled letter, and it differentiates a stop from a fricative. The first one is easier to understand, so we'll start there. With very few exceptions ("Issachar" in the Bible, some modern loan words from Arabic, and others), a double letter in Hebrew in written as a single letter with a dagesh. So, for example, shabbat is written not with a double bet but with a dagesh in a single bet.
"Newspaper" is itton, written ayin-tav-vav-nun with a dagesh in the tav. (And readers with a good memory can now recognize the /i/-sound, represented by a hirik under the ayin, as epenthesis. The word would otherwise start with three consonants: ayin-tav-tav.) Double letters in modern Hebrew (like English and unlike, say, Arabic or Italian) are usually pronounced the same as single letters, so the double-T of itton and the double-B of shabbat sound just like a single-T and single-B. This doubling dagesh, known as a "strong" dagesh, is purely a matter of orthography.
The second use of dagesh is more complicated. Some consonants (in any language) involve a complete blockage of airflow somewhere in or around the mouth. The area "in or around the mouth" is called the "vocal tract," and these consonants are called "stops." They stop the flow of air through the vocal tract. /B/ is such a sound, as is /k/. (They can be further described by where the blockage occurs. /B/ is a labial stop, formed by bringing the lips together. /T/ is palatal, formed with the tongue touching the soft palate of the mouth. Etc.)
By contrast, other consonants are formed by narrowing but not actually closing some part of the vocal tract. These are called fricatives.
One way to tell the difference is to note that, because it actually blocks the air flow, a stop cannot be elongated, while a fricative can.
So /v/, which be exaggerated into vvvvvvvv, and /z/, which can become zzzzzzzz, are both fricatives. While /b/ and /k/ can be repeated (b-b-b-b-b), and while a vowel associated with them can be prolonged (beeeeeeeee), the sounds themselves are single points in time. Stops are like that.
Here's why we care: Some Hebrew letters represent both a stop and a fricative that are made in the same place, or almost the same place, in the vocal tract. In these letters, a dagesh sits in the stop, while the non-dagesh version is the fricative. So compare the kaf and khaf. The former is a stop, and the latter the corresponding fricative. Similarly, the letter peh represents labial sounds. With a dagesh it's the (bi-)labial stop /p/, and without it, the (dento-) labial fricative /f/.
Originally, six Hebrew letters had dual stop/fricative roles, and all six followed the same pattern. The set is known by the mnemonic beged kefet (bet-gimel-daled kaf-peh-tav), which by chance means "clothing of knot," and which happens also to be the name of an extraordinary American musical group. In modern Hebrew, only three letters, bet (B/V), kaf (K/Kh), and peh (P/F) still alternate in sound like this.
In Ashkenazi Hebrew we find a fourth alternation in tav: T/S. This makes sense, because both /t/ and /s/ are palatal sounds. In some Sephardi dialects we find even more alternations.
There's a seventh letter that gets a dot, but even though it looks like a dagesh - after all, how different can one dot look from the next? - it's a mappik, not a dagesh, and it can only be found in the letter heh at the end of a word. It's purpose is to indicate that the heh is functioning as the consonant H rather than merely supporting a final /a/ vowel. (The difference is largely academic now, because neither heh is pronounced in Israeli Hebrew.) The really interesting question, of course, is when the beged kefet letters get a dagesh, but, sadly, that will have to wait. As a prelude of things to come, though, I'll point out that the ubiquitous "beged kefet b'rosh mila" ("beged kefet [letters get a dot] at the start of a word") isn't quite right.
The writer teaches at HUC-JIR in New York City. www.Lashon.net