1.2 Spanish Numbers 0-30
Los números del al
Learning numbers in Spanish begins with the basic sequence ranging from zero to ten. The specific terms and their numerical representations are as follows: the number is called cero; is uno; is identified as dos; is tres; is written as cuatro; is cinco; is called seis; is siete; is called ocho; is nueve; and finally, the number is diez. This series forms the fundamental basis for constructing more complex numbers within the language's decimal number system.
La serie numérica del al
The numbers in the range from 11 to 15 have unique lexical forms that must be memorized individually, as they do not follow the regular combination pattern found in subsequent numbers. The number 11 is called once; 12 is doce; 13 is identified as trece; 14 is catorce; and the number 15 is written as quince.
Formación de los números del al
Starting with the number 16, the linguistic structure begins to exhibit a compositional pattern based on the number ten. The number 16 is written as dieciséis, which includes an accent mark on the final syllable. Following this logic, 17 is named diecisiete; 18 is identified as dieciocho; and 19 is written as diecinueve. It is important to note that these numbers are written as a single word that fuses the prefix derived from diez (ten) with the corresponding digit.
La decena del y los números del al
The number 20 is designated by the word veinte. For numbers between 21 and 29, a single-word structure beginning with the prefix veinti- is used. The complete list for this range is: 21 is veintiuno; 22 is veintidós (with an accent mark); 23 is veintitrés (with an accent mark); 24 is written as veinticuatro; 25 is veinticinco; 26 is veintiséis (with an accent mark); 27 is veintisiete; 28 is veintiocho; and 29 is called veintinueve. As in the previous series, the use of orthographic accent marks is observed in specific numbers to maintain correct stress according to Spanish rules.
El número
Upon reaching the next multiple of ten, the number 30 is identified by the term "treinta." This number marks the end of the current study sequence in this tutorial.
Reglas gramaticales y variaciones de género para el número uno y sus compuestos
There are specific grammatical rules affecting the number one and numbers ending in one—such as veintiuno—when they function as adjectives before a noun. Before a masculine noun, the word uno is shortened (via apocope) to the form un. For example, one says un hombre instead of uno hombre. Similarly, the number 21 becomes veintiún when it precedes a masculine noun, as in the example veintiún hombres.
In the case of feminine nouns, the word uno changes its ending to una; thus, one uses una mujer. Following this rule for compound numbers, the number 21 changes to the form veintiuna when placed before a feminine noun, resulting in the construction veintiuna mujeres.
Observaciones especiales sobre el conteo y la posición del número (¡ojo!)
It is essential to pay attention to specific contexts regarding the use of the words uno and veintiuno. First, these are the standard forms to be used when counting abstractly or in a simple numerical sequence—for example: uno, dos, tres… veinte, veintiuno, veintidós, and so on.
Second, the full form of these numbers must be retained when they follow a noun, even if that noun is feminine. A clear example of this usage is the expression la lección uno. In this case, although lección is a feminine noun, the number does not change to una because it appears after the noun as part of a sequential enumeration or identification.