Some Arabic letters and sounds have no counterparts in the English alphabet and the English orthography. There are nine Arabic sounds which have no equivalence in the English alphabet. These are ( ح خ ص ض ط ظ ع غ ق ). Some translators underline the closest English letters to these Arabic sounds (and letters at the same time), in order to tell readers that these are pronounced differently in Arabic. The closest English letters expressing the Arabic sounds (and letters) in parentheses, from right to left, are ( h, kh, s, dh, t, tdh, a, gh, q ). However, underlining them as ( h, kh, s, dh, t, tdh, a, gh, q ) conveys the message that these are different from the English sounds expressed by the letters of the English alphabet.

The two Arabic letters and sounds of Tha ( ث ) and Dhal ( ذ ), expressed by the two English letters "th" at the beginning of the English words "three" and "that," are transliterated as / th / and / th /, respectively.

This author uses this same method of underlining these letters, with the exception of the two Arabic letters expressed by the / h / and / a / sounds. Instead of underlining them, he adds an apostrophe before the letter to become / 'h / and / 'a / respectively. Using an apostrophe instead of underling a letter is for practical reasons only. First, these two letters are more frequently used than the other letters in the list. Second, it is easier to use the apostrophe on keyboards than adding underlining after writing.

As an example, an apostrophe is used before the English letter / a / to express the eighteenth letter of the Arabic alphabet / 'ayn /, as in the case of transliterating the common Arabic name, 'Abdullah.

An apostrophe is also used before the English letter / h / to express the sixth letter of the Arabic alphabet / 'ha /, as in the case of translating the common Arabic name 'Halima.