Why do some of the Hebrew letters have dots in them, and why do the same letters, in the same words, sometimes appear with dots and sometimes without?
A prime example of this phenomenon is the name of the Egyptian king, Pharaoh, פרעה. In Hebrew, his name is usually pronounced as "Par-oh," but sometimes it's read as "Far-oh."
To explain this, allow me to share with you some background information about Hebrew pronunciation:
There are six Hebrew letters that have both "hard" and "soft" sounds (or, to use the technical terms, they are both plosive and fricative consonants). We put a dot, called a dagesh, in middle of these letters to let the reader know that in this instance the letter is "hard" (or plosive).
The hard בּ is pronounced "b". The soft ב is pronounced "v".
The hard כּ is pronounced "k". The soft כ is pronounced "ch" (as in challah).
The hard פּ is pronounced "p". The soft פ is pronounced "f".
The other three letters are more confusing. Among some groups, the distinction between the hard and soft form has gotten lost. Other groups have preserved the distinction.
Jews from Ashkenazic lands traditionally pronounce תּ as "t" and ת as "s". In Sephardic communities the difference in pronunciation is more subtle. In modern Hebrew they are both pronounced as "t".
Most Jews pronounce both גּ and ג as a hard "g". Some Yemenite Jews pronounce גּ as "j" and ג as a hard "g".
Most Jews pronounce both דּ and ד as "d". Some groups pronounce דּ as "d" and ד as "th," as in the word "then."
So by now you know that the Hebrew word "פרעה" can be pronounced either "Far-oh" or "Par-oh," depending on whether the פ has a dot.
If you just want to know how to read Hebrew, you can stop reading now. If you are a grammar geek and like knowing the principles behind the pronunciation, read on.
The doubly endowed letters ב, ג, ד, כ, פ, ת get dotted when they start a word. However, when a word beginning with ב, ג, ד, כ, פ, ת is preceded by a word ending with a vowel sound, these letters may not get a dot. This rule is subject to change, based on the cantillation of the verse.
Here are some examples:
Exodus 1:19: "וַתֹּאמַרְןָ הַמְיַלְּדֹת אֶל פַּרְעֹה" ("And the midwives said to Pharaoh"). Notice the dot in the פ, because the word follows a ל, a consonant. In this verse, the Egyptian king is called "Paroh."
Exodus 2:15: "וַיִּבְרַח מֹשֶׁה מִפְּנֵי פַרְעֹה" ("And Moses ran from before Pharaoh"). The word מִפְּנֵי, "from before," ends with a vowel sound, thus the פ following is not dotted, and Moses' nemesis is called "Faroh."
Exodus 1:11 shows us an instance in which the first letter of Pharaoh's name is not the first letter of the word: "וַיִּבֶן עָרֵי מִסְכְּנוֹת לְפַרְעֹה" ("And [the Israelites] built store cities for Pharaoh"). That ל before פַרְעֹה means "for." Because the פ is not the first letter in the word, it is not dotted and the slave-driving monarch is called "Faroh."
However, ב, ג, ד, כ, פ, ת are dotted in the middle of a word if they are preceded by a consonant sound.
There are more rules governing the pronunciation of ב, ג, ד, כ, פ, ת, but the ones stated above are the most basic.
Hebrew grammar can be quite confusing. If there's anything you don't understand feel free to write back.
Rabbi Eliezer Posner