The 26-letter pronunciation of x is: /?ks/.

This letter usually appears as "eks" in English words. When spelled, we pronounce it as "eks" rather than simply as the name of the letter "X".

In English, the letter "X" is a relatively rare but very important letter. It is widely used in spelling, not only to construct common words, but also as symbols and codes in science, mathematics, technology and other fields. Here are some common English words starting with "X":

1. X-ray: X-ray, a non-destructive testing technology used for medical diagnosis and scientific research.

2. Xenophobia: Xenophobia, unreasonable or excessive fear or hostility towards foreigners or foreign cultures.

3. Xylophone: Xylophone, a percussion instrument, usually made of wood, with soundboards of different scales.

4. Xerox: (verb) to copy, usually refers to copying using a Xerox brand copy machine.

In addition to common words, the letter "X" is also widely used in code names, trademarks, brand names, etc. For example, SpaceX is the name of an American aerospace company, and the "X" in it stands for "exploration".

In addition, the letter "X" also represents an unknown number or variable in mathematics. In algebraic equations, "X" is often used to represent the numerical value we need to solve or find.

In general, although the letter "X" is located later in the alphabet, it plays an important role in English and other subject areas. By mastering the pronunciation and application of the letter "X", we can better understand and use the English language, as well as better apply its special meanings in other subjects and fields.