Letter (alphabet)

Letters make words.

They stand for sounds we say.

You can see big and small letters. Some are called capital letters. They go at the start of names. We put letters in a special order. This is called alphabetical order. Letters can even act like numbers. They help us tell stories. Can you find a letter?

Letters are small shapes used in writing. Each letter stands for a sound in speech. We call these sounds phonemes. When we put letters together, we make words.

Sometimes, two or three letters work together. They make one sound. For example, "sh" and "tch" are groups of letters.

Most writing uses two types of letters. We call them uppercase and lowercase.

Uppercase letters are also called capital letters. We use them for names or at the start of sentences. Lowercase letters are smaller. Long ago, printers kept these in different drawers. They kept capitals in the top case. This is why we call them uppercase.

Writing has a long history. Long ago, people used pictures for words. Then, the Phoenicians made a script with only consonants. The Greeks added vowels to their letters. Later, the Romans made the Latin alphabet. We use many versions of these today. Some letters even look the same in different languages. But they might sound different!

Letters also help us in math and science. They can even act as numbers.

Letters are the building blocks of writing. Each letter is a small shape called a grapheme. These shapes usually match a sound in speech called a phoneme. You can think of letters like pieces of a puzzle. When you put them together, you form written words. Sometimes, one sound needs more than one letter. These groups are called multigraphs. For example, the letters "ch" or "sh" work together in English.

Most writing systems use two different styles of letters. These are called uppercase and lowercase letters. We often call uppercase letters "capitals." People use them for the start of sentences or for names. They also use them for titles and big headings. Lowercase letters are smaller and used for most writing. The names come from old printing presses. Printers kept metal letter blocks in wooden drawers. They kept the big capital letters in the upper case. The smaller letters stayed in the lower case.

Writing has changed a lot over a very long time. Long ago, people used pictures to show words or sounds. The earliest examples of letter-like signs come from Ancient Egypt and China. Around 1050 BCE, the Phoenicians created a script with 22 letters. These were only consonant sounds. Later, the Greeks adapted this script. They added four letters to represent vowels. This was a big step for writing.

The Latin alphabet is one of the most famous systems. It grew from the Greek and Etruscan scripts. The Roman Empire helped refine it around 500 BCE. Most people in the western world use versions of it today. Over time, some letters were dropped, like "thorn" or "wynn." Other letters changed how they looked. Even today, letters can look the same but sound different. For example, the Latin "H" and Greek "eta" look alike. But they represent different sounds in their own languages.

Letters do much more than just make words. They are used in many parts of our lives. In math and science, letters represent ideas or numbers. Some letters even act as numbers, like Roman numerals. We also see letters in names of objects. An "A-frame" or an "O-ring" uses a letter shape for its name. In computers, every letter has its own special code. This helps machines understand exactly which letter you want to type.

A letter is a specific type of grapheme, which is the smallest functional unit in a writing system. Most letters correspond to a phoneme, the smallest unit of sound in spoken language. While they are closely linked, there is rarely a perfect one-to-one match between a single letter and a single sound. In many alphabets, letters are combined to build written words, just as phonemes are combined to build spoken ones. Sometimes, a single sound requires multiple letters working together. These sequences are known as multigraphs. In English, two-letter groups like "ch" or "sh" are called digraphs. Three-letter groups, such as "tch," are called trigraphs.

Writing systems often use different versions of the same letter, known as allographs. Many scripts utilize two main types: uppercase, also called majuscule, and lowercase, or minuscule. These forms represent the same sound but serve different structural roles. Capital letters are typically used for the start of sentences, proper names, titles, or headers. In the German language, for instance, all nouns must begin with a capital letter. The terms "uppercase" and "lowercase" come from the history of printing. Printers kept metal type in wooden drawers called cases. They stored the larger capital letters in the upper case and the smaller letters in the lower case.

Many alphabets also use diacritics, which are marks or accents added to letters. These marks change how a letter is pronounced. While English rarely uses diacritics except in loanwords like "naïve" or names like "Brontë," they are common in many other languages. In modern computing, these marks are often handled as precomposed characters. This allows computers to recognize specific accented letters as single units.

Before modern alphabets, humans used various phonograms to represent sounds. These included verbal pictures for entire words and syllabic systems that represented word articulations. The earliest alphabetic examples appear in Ancient Egypt and Ancient China around 1050 BCE. A major turning point occurred around 1050 BCE with the Phoenician alphabet. The Phoenicians were Semitic workers in Egypt who developed a script of 22 letters. This original script was written and read from right to left.

The evolution of writing continued as the Phoenician script influenced other cultures. The Etruscan and Greek alphabets both emerged from the Phoenician system. The Greek alphabet was revolutionary because it was the first to assign letters to both consonants and vowels. The Latin alphabet, which is the most widely used today, emerged from these earlier traditions. The Roman Empire refined the Latin alphabet starting around 500 BCE. During the fifth and sixth centuries, the development of lowercase letters began to emerge in Roman writing. By the late 7th and early 8th centuries, writing also developed paragraphs, sentences, and clauses.

Letters have a massive influence on modern science, math, and engineering. They are often used as symbols to represent complex ideas or variables. In some systems, letters also function as numerals, such as in Roman numerals. Letters can even be used to name objects based on their physical shapes. Examples include an "A-frame," an "O-ring," or a "U-bend." We also see letters used as abbreviations, such as "G-man" for a government agent. In many scientific fields, specific letters are used to identify rays, such as alpha, beta, and gamma rays.

Because letters are used across many different cultures, they often overlap in surprising ways. Some letterforms are homoglyphs, meaning they look identical but represent different sounds. For example, the Latin "H," the Greek "eta," and the Cyrillic "en" look similar but are distinct phonemes. Conversely, different shapes can represent the same sound. The Greek "sigma" and the Cyrillic "es" both represent the /s/ sound. In the digital age, every letter is assigned a unique code point in computer systems. This ensures that a letter typed in one part of the world is understood correctly everywhere else.