décimo

The Spanish word décimo is an ordinal number that translates to 'tenth' in English. It is primarily used to denote the specific position of an item in a sequence that follows the ninth and precedes the eleventh. In the Spanish language, ordinal numbers function as adjectives, which means they must agree in gender and number with the noun they modify. Therefore, you will encounter décimo (masculine singular), décima (feminine singular), décimos (masculine plural), and décimas (feminine plural). This word is fundamental for anyone learning Spanish because it appears in everyday contexts ranging from addresses and floor numbers to historical references and even the national lottery.

Grammatical Agreement

When describing a feminine noun like 'la planta' (the floor), you must change the ending: 'la décima planta'. If you are talking about multiple tenth-place winners in different categories, you might say 'los décimos lugares'.

Beyond its mathematical definition, décimo holds a special place in Spanish culture, particularly in Spain. It refers to a one-tenth share of a lottery ticket, specifically for the famous 'Lotería de Navidad' (Christmas Lottery). Because full tickets are expensive, they are divided into ten 'décimos'. When people talk about 'comprar un décimo', they aren't just buying a 'tenth'; they are participating in a massive national tradition. This cultural nuance is vital for learners to understand, as the word becomes a noun in this specific context. Furthermore, in poetry and music, a décima refers to a ten-line stanza, a popular form in Latin American folk music and classical Spanish literature. Understanding these layers helps a learner transition from basic A1 counting to deeper cultural fluency.

Placement

Ordinal numbers like décimo can be placed before or after the noun. 'El décimo capítulo' and 'El capítulo décimo' are both correct, though placing it before is more common in modern speech.

In mathematical and scientific contexts, décimo is used to describe fractions. 'Un décimo' means one-tenth (1/10). This is crucial for measurements and percentages. If something increases by a tenth, you would use this term. It is also the root for 'decimal', which is used exactly as it is in English. For A1 learners, the focus is usually on the sequence: primero, segundo, tercero... all the way to décimo. After ten, Spanish often reverts to cardinal numbers (once, doce) in casual speech, making 'décimo' one of the last ordinal numbers you truly need to master for daily conversation. Using it correctly demonstrates a high level of grammatical control even at the beginner stages of learning Spanish.

Regional Variation

In some Latin American countries, 'décimo' is also used to refer to a 'thirteenth-month' salary bonus, often called the 'décimo tercer sueldo'.

Using décimo in a sentence requires attention to the noun it is describing. As an adjective, its primary job is to provide detail about the order or quantity of a noun. In Spanish, adjectives usually follow the noun, but ordinal numbers like décimo are a frequent exception; they often precede the noun to emphasize the position within a sequence. For example, 'el décimo piso' (the tenth floor) is the standard way to express an address. If you were to say 'el piso décimo', it sounds slightly more formal or technical, perhaps as if you are reading from a directory. This flexibility allows for subtle shifts in tone that learners can use to sound more natural.

Gender Matching

Always identify the gender of the noun. 'Aniversario' is masculine, so it is 'décimo aniversario'. 'Etapa' (stage/phase) is feminine, so it is 'décima etapa'.

When using décimo to talk about fractions, it often appears with the word 'parte'. 'La décima parte' literally means 'the tenth part', or 10%. This is common in financial, mathematical, or descriptive contexts where you are dividing a whole. For instance, 'Solo una décima parte de los estudiantes aprobó' (Only a tenth of the students passed). In this case, 'décima' is feminine because it modifies 'parte'. If you are using it as a noun to refer to a lottery ticket, it is always masculine: 'Tengo un décimo para el sorteo de mañana'. Here, the word 'décimo' stands alone because the noun 'billete' (ticket) is implied but omitted.

Pluralization

If you are referring to multiple 'tenths' or the tenth items in multiple sets, use 'décimos' or 'décimas'. For example, 'Los décimos premios fueron entregados al final'.

Another common use case is in the titles of monarchs or popes, though this is becoming more archaic in speech. While we might write 'Alfonso X', we say 'Alfonso décimo'. This follows the rule that for royalty from 1 to 10, ordinals are used, but from 11 onwards, cardinals are used (e.g., Alfonso once). For a learner, mastering this allows for correct pronunciation when reading history books or visiting historical sites in Spain or Latin America. In modern academic writing, décimo is also used to categorize centuries, such as 'el siglo décimo', although 'el siglo diez' is also heard in less formal contexts. Consistency in using the ordinal form marks a speaker as well-educated in the language.

Compound Ordinals

'Décimo' is the base for 11th through 19th: 'decimoprimero' (11th), 'decimosegundo' (12th), etc. Note how they combine into one word.

If you walk through the streets of Madrid or Mexico City, you will likely hear décimo in several specific environments. The most prominent is the elevator. In high-rise buildings, 'el décimo piso' is a common destination. You'll hear people asking, '¿A qué piso va?' and answering, 'Al décimo, por favor'. This is a practical, everyday usage that every traveler should know. Another very common place is in sports commentary. Whether it's football (soccer), Formula 1, or athletics, commentators frequently list the positions of players or racers. 'El equipo está en el décimo lugar de la liga' (The team is in tenth place in the league) is a phrase you will hear every weekend during the sports news.

The Lottery (Spain)

In December, the word 'décimo' is everywhere in Spain. People sell them in 'administraciones de lotería', on the street, and in bars. It refers to the physical ticket which is 1/10th of a full sheet.

In educational settings, teachers use décimo to refer to grades or years of study, particularly in countries like Colombia or Ecuador where 'décimo grado' corresponds to a specific year in high school. You will hear students say, 'Estoy en décimo', meaning they are in the tenth grade. In a broader academic sense, when discussing history or literature, professors will refer to the 'siglo décimo' (10th century) or 'el décimo canto' (the tenth canto) of an epic poem. This usage is more formal but very common in universities and museums. Even in casual conversation, when someone is listing complaints or reasons, they might reach their tenth point and say, 'Y en décimo lugar...', though usually, people stop using ordinals after 'quinto' or 'sexto' and switch to 'y por último'.

Professional Contexts

In law or administration, you might hear 'la décima cláusula' (the tenth clause) of a contract. Precision is key in these fields, so ordinals are used strictly.

Lastly, in the medical field or when discussing weather, you might hear about 'décimas de fiebre'. Interestingly, in Spanish, if someone has a very slight fever (like 37.2°C), they don't say they have a full 'fiebre', they say 'tiene unas décimas' (he has a few tenths [of a degree]). This is a very common idiomatic way to describe being slightly unwell. Similarly, in track and field, a race might be won by 'unas décimas de segundo' (a few tenths of a second). In all these cases, the word décimo and its derivatives help Spanish speakers describe the world with precision, whether they are talking about winning millions in the lottery, measuring a child's temperature, or identifying which floor the dentist is on.

Music and Arts

Musicians might refer to a 'décima' interval, though it's less common than 'octava'. In art history, the 'décima musa' (tenth muse) is a title often given to the Mexican poet Sor Juana Inés de la Cruz.

One of the most frequent errors for English speakers learning Spanish is the failure to make décimo agree in gender with the noun it modifies. In English, 'tenth' is immutable; it doesn't matter if you are talking about a tenth boy or a tenth girl. In Spanish, however, you must switch between décimo and décima. Saying 'la décimo vez' is a common mistake; it must be 'la décima vez'. This requires the learner to constantly be aware of the gender of the noun they are about to say, which is one of the hardest habits to build in Spanish. Another common mistake is the misuse of accents. The word décimo has an 'esdrújula' stress pattern (stress on the third-to-last syllable), which in Spanish always requires a written accent on the vowel: décimo. Forgetting this accent is a major spelling error.

Ordinal vs Cardinal

Learners often use the cardinal 'diez' when they should use 'décimo'. While 'el piso diez' is acceptable in many regions, 'el décimo aniversario' is much more standard than 'el aniversario diez'.

Another area of confusion is the 'apocope' or shortening of ordinal numbers. Beginners learn that 'primero' becomes 'primer' and 'tercero' becomes 'tercer' before a masculine singular noun (e.g., 'el primer día'). Naturally, many students try to apply this to other ordinals, saying 'el décim día'. This is incorrect. Décimo does not have a shortened form. It remains décimo regardless of its position. Furthermore, learners often confuse décimo with diezmo. While they share a Latin root, diezmo specifically refers to a tithe (a 10% religious tax or donation). Using diezmo to mean 'tenth' in a general sense will cause significant confusion. Similarly, 'decimal' should only be used in mathematical contexts regarding the base-10 system, not for ranking items in a race.

Numbering Kings and Popes

A common mistake is using cardinals for all royalty. Remember: 1-10 use ordinals (Carlos Quinto, Alfonso Décimo), but 11+ use cardinals (Alfonso Trece).

Finally, there is the issue of 'decimoprimero' (11th) and 'decimosegundo' (12th). Many learners try to say 'diez y primero' or 'décimo uno', which are both incorrect. When combining 'décimo' with other ordinals to form numbers 11-19, they typically merge into a single word. While 'undécimo' and 'duodécimo' are also correct for 11th and 12th, 'decimoprimero' is very common. However, for A1-A2 learners, the most important thing is to get 'décimo' itself right before worrying about these complex compounds. Also, avoid using 'décimo' for dates; in Spanish, we say 'el diez de octubre', not 'el décimo de octubre'. The only exception is 'el primero' for the first of the month. Using 'décimo' for the 10th of the month is a classic 'Anglicism' (applying English rules to Spanish) that should be avoided to sound more authentic.

Lottery Confusion

In Spain, if you ask for 'un décimo', you are asking for a lottery ticket. If you mean 'a tenth of a pizza', say 'una décima parte de la pizza'.

When you want to express the idea of 'tenth' or something related to the number ten, décimo is your primary tool, but it is not the only one. Depending on the context—whether you are talking about fractions, groups, or sequences—you might choose a different word. The most obvious alternative is the cardinal number diez. In many casual situations, especially in Latin America, speakers substitute ordinals with cardinals for numbers above ten, and sometimes even for ten itself. For example, instead of 'el décimo piso', you will often hear 'el piso diez'. This is technically less formal but very common in spoken Spanish. Knowing when to use 'diez' versus 'décimo' is a key part of sounding like a native speaker.

décimo vs. diezmo

While 'décimo' is the position (10th), 'diezmo' is the noun for a tithe or a tenth part given as tax. They are not interchangeable.

décimo vs. deceno

'Deceno' is an archaic or very formal adjective meaning 'consisting of ten'. You will rarely hear this in modern Spanish.

Another related word is decena. While décimo refers to the tenth item in a line, decena refers to a group of ten items (like a 'dozen' but for ten). For example, 'una decena de huevos' means ten eggs. This is useful for quantifying groups rather than positions. In mathematics, you have decimal. This is used for the decimal system (sistema decimal) or decimal points (punto decimal). If you are referring to the fractional part of a number, you might use décima as a noun. For example, '3.1' is 'tres con una décima'. This is very common in technical and scientific Spanish. Furthermore, 'décima' can also refer to the poetic stanza mentioned earlier, which is a specific literary term.

décimo vs. undécimo

'Undécimo' is the next in the sequence (11th). It is often confused with 'decimoprimero'. Both are correct, but 'undécimo' is more traditional.

In some contexts, you might use decimales to refer to the digits after a decimal point. If someone asks you to 'redondear al décimo más cercano', they are using a direct translation of English that is understood but more properly expressed as 'redondear a la primera cifra decimal'. Lastly, consider the word decuplicar (to increase tenfold). While not a synonym for 'décimo', it belongs to the same semantic family of 'ten-related' words. For a learner, the most important distinction is between 'décimo' (the 10th one) and 'diez' (ten of them). Once you have that down, adding 'decena' (a group of ten) and 'décima' (a tenth part or a slight fever) will significantly round out your ability to discuss numbers and order in Spanish.

Summary Table

- Décimo: 10th (Position)
- Diez: 10 (Quantity)
- Decena: A set of 10
- Diezmo: Tithe (Religious/Historical)
- Décima: 1/10th or a 10-line poem.