ArticleslgStudy

science

A

A is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand A rather than just read about it. In short: A (minuscule: a) is the first letter and the first vowel letter of the Latin alphabet, used in the modern English alphabet, and others worldwide. Its name in English is a (pronounced as in say), plural aes.

A — main illustration
A — illustration

Key takeaways

  • A belongs to science; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect A to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of A from memory before moving on to harder problems.

Reference excerpt

A (minuscule: a) is the first letter and the first vowel letter of the Latin alphabet, used in the modern English alphabet, and others worldwide. Its name in English is a (pronounced as in say), plural aes. It is similar in shape to the Ancient Greek letter alpha, from which it derives. The uppercase version consists of the two slanting sides of a triangle, crossed in the middle by a horizontal bar. The lowercase version is often written in one of two forms: the double-storey |a| and single-storey |ɑ|. The latter form is commonly used in handwriting and fonts based on it, especially fonts intended to be read by children, and is also found in italic type.

Name In English, the name of the letter is the long A sound, pronounced . Its name in most other languages matches the letter's pronunciation in open syllables.

History The earliest known ancestor of A is aleph—the first letter of the Phoenician alphabet—where it represented a glottal stop [ʔ], as Phoenician only used consonantal letters. In turn, the ancestor of aleph may have been a pictogram of an ox head in proto-Sinaitic script influenced by Egyptian hieroglyphs, styled as a triangular head with two horns extended. When the ancient Greeks adopted the alphabet, they had no use for a letter representing a glottal stop—so they adapted the sign to represent the vowel /a/, calling the letter by the similar name alpha. In the earliest Greek inscriptions dating to the 8th century BC following the Greek Dark Ages, the letter rests upon its side. However, in the later Greek alphabet it generally resembles the modern capital form—though many local varieties can be distinguished by the shortening of one leg, or by the angle at which the cross line is set. The Etruscans brought the Greek alphabet to the Italian Peninsula, and they left the form of alpha unchanged. When the Romans adopted the Etruscan alphabet to write Latin, the resulting form used in the Latin script would come to be used to write many other languages, including English.

Typographic variants

During Roman times, there were many variant forms of the letter A. First was the monumental or lapidary style, which was used when inscribing on stone or other more permanent media. There was also a cursive style used for everyday or utilitarian writing, which was done on more perishable surfaces. Due to the perishable nature of these surfaces, there are not as many examples of this style as there are of the monumental, but there are still many surviving examples of different types of cursive, such as majuscule cursive, minuscule cursive, and semi-cursive minuscule. Variants also existed that were intermediate between the monumental and cursive styles. The known variants include the early semi-uncial (c. 3rd century), the uncial (c. 4th–8th centuries), and the late semi-uncial (c. 6th–8th centuries).

At the end of the Roman Empire (5th century CE), several variants of the cursive minuscule developed through Western Europe. Among these were the semi-cursive minuscule of Italy, the Merovingian script in France, the Visigothic script in Spain, and the Insular or Anglo-Irish semi-uncial or Anglo-Saxon majuscule of Great Britain. By the ninth century, the Caroline script, which was very similar to the present-day form, was the principal form used in book-making, before the advent of the printing press. This form was derived through a combining of prior forms.

15th-century Italy saw the formation of the two main variants that are known today. These variants, the Italic and Roman forms, were derived from the Caroline Script version. The Italic form ⟨ɑ⟩, also called script a, is often used in handwriting; it consists of a circle with a vertical stroke on its right. In the hands of medieval Irish and English writers, this form gradually developed from a 5th-century form resembling the Greek letter tau ⟨τ⟩. The Roman form ⟨a⟩ is found in most printed material, and consists of a small loop with an arc over it. Both derive from the majuscule form ⟨A⟩. In Greek handwriting, it was common to join the left leg and horizontal stroke into a single loop, as demonstrated by the uncial version shown. Many fonts then made the right leg vertical. In some of these, the serif that began the right leg stroke developed into an arc, resulting in the printed form, while in others it was dropped, resulting in the modern handwritten form. Graphic designers refer to the Italic and Roman forms as single-decker a and double decker a respectively. Italic type is commonly used to mark emphasis or more generally to distinguish one part of a text from the rest set in Roman type. There are some other cases aside from italic type where script a ⟨ɑ⟩, also called Latin alpha, is used in contrast with Latin ⟨a⟩, such as in the International Phonetic Alphabet.

Use in writing systems In English, ⟨a⟩ is the indefinite article (with the alternative form an when followed by a vowel).

Pronunciation

English

In modern English orthography, the letter ⟨a⟩ represents at least seven different vowel sounds, here represented using the vowels of Received Pronunciation, with effects of ⟨r⟩ ignored and mergers in General American mentioned where relevant:

the near-open front unrounded vowel /æ/ as in pad the open back unrounded vowel /ɑː/ as in father—merged with /ɒ/ as /ɑ/ in General American—which is closer to its original Latin and Greek sound the open back rounded vowel /ɒ/ (merged with /ɑː/ as /ɑ/ in General American) in was and what the open-mid back rounded vowel /ɔː/ in water the diphthong /eɪ/ as in ace and major, usually when ⟨a⟩ is followed by one, or occasionally two, consonants and then another vowel letter—this results from Middle English lengthening followed by the Great Vowel Shift a schwa /ə/ in many unstressed syllables, as in about, comma, solar The double ⟨aa⟩ sequence does not occur in native English words, but is found in some words derived from foreign languages such as Aaron and aardvark. However, ⟨a⟩ occurs in many common digraphs, all with their own sound or sounds, particularly ⟨ai⟩, ⟨au⟩, ⟨aw⟩, ⟨ay⟩, ⟨ea⟩ and ⟨oa⟩. ⟨a⟩ is the third-most-commonly used letter in English after ⟨e⟩ and ⟨t⟩, as well as in French; it is the second most common in Spanish, and the most common in Portuguese. ⟨a⟩ represents approximately 8.2% of letters as used in English texts; the figure is around 7.6% in French 11.5% in Spanish, and 14.6% in Portuguese.

… excerpt ends here. Continue reading the full article.

Illustrations

A illustration
A: Pronunciation of the name of the letter ⟨a⟩ in European languages. /a/ and /aː/ can differ phonetically between [a], [ä], [æ] and [ɑ] depending on the language.
Pronunciation of the name of the letter ⟨a⟩ in European languages. /a/ and /aː/ can differ phonetically between [a], [ä], [æ] and [ɑ] depending on the language.
A illustration
A illustration
A illustration

Worked examples

Example 1 — a first encounter with A

Start with the simplest possible case. Write down what A claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to A before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about A ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of A

In research
A appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses A in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
A is common in secondary-school and first-year university syllabi. It links to neighbouring topics ISO basic Latin letters, Vowel letters, so understanding it makes those chapters shorter.
In everyday life
Look for A outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study A in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what A means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain A out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is A in simple terms?

A (minuscule: a) is the first letter and the first vowel letter of the Latin alphabet, used in the modern English alphabet, and others worldwide. Its name in English is a (pronounced as in say), plural aes.

Why does A matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study A?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on A.

Tags

  • ISO basic Latin letters
  • Vowel letters

Keep exploring