The Libro de estilo de la Justicia (the style guide for the Spanish justice system), published in 2017 by the Real Academia Española (RAE, the Royal Spanish Academy) and the Consejo General del Poder Judicial (CGPJ, Spain's General Council of the Judiciary) under the direction of Santiago Muñoz Machado, is the reference for writing a legal text well in Spanish. It can be read free of charge on the RAE website. These are the mistakes that come up most often in claims, appeals and reports, with what it proposes instead.
This guide is about writing legal Spanish, so the examples stay in Spanish, in «», with their meaning in English.
It is not a proofreader's obsession. The 2011 Report of the Comisión para la Modernización del Lenguaje Jurídico (the Commission for the Modernisation of Legal Language) noted that, according to the CGPJ's opinion surveys, 82% of citizens find legal language excessively complicated and hard to understand. A clear brief also reads better in court.
Phrases the guide asks you to change
«En base a»
The Libro de estilo criticises «en base a» (on the basis of) and proposes sobre la base de, con base en, basándose en or de acuerdo con (all meaning roughly on the basis of, or in accordance with). It is one of the most widespread in legal documents: «en base a lo expuesto» (on the basis of the foregoing) becomes «sobre la base de lo expuesto» or, more simply, «de acuerdo con lo expuesto». It is worth knowing that the Diccionario panhispánico de dudas (the RAE's dictionary of usage questions), in its current edition, is more tolerant and considers it acceptable though less advisable; the reference book for the justice system, on the other hand, advises against it.
«En aras a» and «en relación a»
The correct form is en aras de (for the sake of: «en aras de la seguridad jurídica», for the sake of legal certainty), and the guide asks you not to use it as a mere synonym of «para» (for, in order to). It also prefers en relación con (in relation to) to «en relación a», although in this case the Diccionario panhispánico de dudas no longer criticises it, because it is so widely used.
«Queísmo» and «dequeísmo»
These are the names for wrongly dropping or wrongly adding «de» before «que» (that). Some phrases require the «de»: a pesar de que (even though), en caso de que (in case), no cabe duda de que (there is no doubt that), estar seguro de que (to be sure that). And some verbs do not allow it: «considero que» (I consider that), not «considero de que». The quick test the guide gives is to turn the sentence into a question: if the question takes «de» («¿de qué está seguro?», what is he sure of?), so does the sentence.
Latin expressions, correctly written
It is written motu proprio (of one's own accord), not «motu propio», and with no preposition in front: neither «de motu proprio» nor «por motu proprio». The same goes for grosso modo (roughly): never «a grosso modo». The guide also recommends writing Latin expressions in italics, although it acknowledges that in legal texts they usually appear in roman type.
The BOE gerund
The guide devotes a whole section to incorrect uses of the gerund (the Spanish form ending in «-ando» or «-iendo», similar to the English «-ing»), and two come up again and again in legal documents:
- Gerund of posteriority («gerundio de posterioridad»): it expresses something that happens afterwards. «El demandado abandonó el inmueble, devolviendo las llaves un mes más tarde» (the defendant left the property, returning the keys a month later) should be «abandonó el inmueble y devolvió las llaves un mes más tarde» (left the property and returned the keys a month later). It is only acceptable if the second action is immediate.
- Specifying gerund («gerundio especificativo»): one that works like an adjective. «Se aprobó una resolución estableciendo los plazos» (a resolution establishing the deadlines was approved) should be «una resolución que establece los plazos» (a resolution that establishes the deadlines). It is so typical of administrative texts that the guide notes it is known as the BOE gerund, after the Boletín Oficial del Estado, Spain's official gazette.
«El mismo» as a pronoun
«Se interpuso recurso de apelación y el mismo fue desestimado.» (An appeal was lodged and the same was dismissed.) The guide calls this an archaic use, far from everyday speech, and adds that it often creates ambiguity: with two nouns before it, it is not always clear which one it refers to. It is almost always enough to remove it or replace it with a relative or a pronoun: «se interpuso recurso de apelación, que fue desestimado» (an appeal was lodged, which was dismissed).
Nominalisations and the passive voice
«Interpone recurso» (lodges an appeal) is «recurre» (appeals); «procede a la notificación» (proceeds to give notice) is «notifica» (gives notice); «efectuar el pago» (to make payment) is «pagar» (to pay). The guide advises against overusing these constructions built on a noun and recommends the active voice: «el juzgado dictó sentencia» (the court gave judgment) is understood sooner than «por el juzgado fue dictada sentencia» (judgment was given by the court). The 2011 Report took the same line: short sentences, in subject, verb and complement order, and the passive only when essential.
Numbers, articles and citations
- Artículo 1902, not 1.902. Numbers that identify an item in a series, such as an article or a law, are written without a thousands point or space (Spanish uses a point as the thousands separator). The guide itself gives the example of article 1566 of the Código Civil (the Spanish Civil Code).
- n.º, not nº. The abbreviation of «número» (number) has the point before the superscript letter: «n.º», and in the plural «n.os». «núm.» and «nro.» are also valid.
- Short citations, from general to specific. The Directrices de técnica normativa published in the BOE (the Spanish guidelines on legislative drafting; guideline 68) cite from the general to the particular and in compact form: «el artículo 6.2.a).1.º, párrafo segundo» (article 6.2.a).1.º, second paragraph). Guideline 73 sets out how to cite a whole law (type, number and year, date and name), and guideline 80 that the first citation is given in full and later ones can be shortened. With examples of each case, in how to cite a law or an article; for case law, in how to cite a court ruling.
Times, centuries and percentages
- Times, with a colon: «a las 17:30» (at 17:30), never «a las 17,30».
- Centuries, in Roman numerals: «siglo XXI» (21st century), not «siglo 21».
- Percentages: «20 %», with a space between the figure and the symbol, or «veinte por ciento» (twenty per cent), in two words.
Feminine forms of legal professions
The masculine form should not be used to refer to a woman: la abogada (the lawyer), la letrada (counsel), la magistrada (the judge or magistrate). With «juez» (judge), both la juez and la jueza are valid, and for «fiscal» (prosecutor) the recommended form is la fiscal, because «fiscala» has hardly caught on. If the title has an adjective, it agrees: «intérprete jurada» (sworn interpreter).
Capital letters: fewer than people use
A capital letter only in the full name of a specific body: «Tribunal Supremo» (Supreme Court), «Juzgado de Primera Instancia n.º 4 de Valencia» (Court of First Instance No. 4 of Valencia), «Sala de lo Penal» (Criminal Division). When it is mentioned again or used generically, lower case: «el juzgado acordó» (the court ordered), «esta sala» (this division). With laws, a capital letter in the official title («Código Civil») and lower case for «ley» (law), «real decreto» (royal decree), «artículo» (article) or «apartado» (paragraph) as common nouns. And job titles, in lower case: «el juez decano» (the senior judge).
«Aperturar»
It is not a synonym of «abrir» (to open). Proceedings («diligencias»), a time limit or a file are opened, and the guide asks you to use «abrir» for that.
Quick reference table
| Avoid | Write | Meaning |
|---|---|---|
| en base a lo expuesto | sobre la base de lo expuesto, con base en lo expuesto | on the basis of the foregoing |
| en aras a | en aras de | for the sake of |
| en relación a | en relación con | in relation to |
| a pesar que | a pesar de que | even though |
| de motu propio | motu proprio | of one's own accord |
| a grosso modo | grosso modo | roughly |
| y el mismo fue desestimado | que fue desestimado | which was dismissed |
| artículo 1.902 | artículo 1902 | article 1902 |
| nº 3 | n.º 3 | No. 3 |
| a las 17,30 | a las 17:30 | at 17:30 |
| siglo 21 | siglo XXI | 21st century |
| la abogado | la abogada | the lawyer (a woman) |
| aperturar diligencias | abrir diligencias | to open proceedings |
Fixing it without thinking about it
Most of these mistakes appear when writing in a hurry, and also when dictating, because they are the way we speak. ablalo applies part of the Libro de estilo automatically. In any dictation it writes articles without a thousands point, centuries in Roman numerals and times with a colon, and it cites paragraphs in the format of guideline 68 («artículo 15.1.a)»). And when you use the assistant's legal register, it also changes «en base a», «en aras a», «en relación a» and «a pesar que», writes «n.º», writes «la abogada» where appropriate and, when rewriting, undoes the gerund of posteriority and the use of «el mismo» as a pronoun. The final review, as always, is yours. How to dictate a brief from start to finish is covered in how to dictate a legal brief.
Sources: RAE and CGPJ, Libro de estilo de la Justicia (in Spanish; A-Z vocabulary and sections 6.1.2, 6.5.2, 6.6, 7.1.1, 7.3.3.3, 8.13.3, 11.4, 13.1, 14.1.2, 14.2.1, 14.5.2, 14.8 and 16.1.3); RAE, Diccionario panhispánico de dudas (in Spanish; entries «base», «relación» and «gerundio»); Directrices de técnica normativa (in Spanish; Resolution of 28 July 2005, guidelines 68, 73 and 80); Comisión para la Modernización del Lenguaje Jurídico, report of recommendations (2011). Checked on 9 October 2026.
Frequently asked questions
Is it «en base a» or «con base en»?
The Libro de estilo de la Justicia criticises «en base a» and proposes «sobre la base de», «con base en», «basándose en» or «de acuerdo con» (all meaning roughly on the basis of, or in accordance with). The Diccionario panhispánico de dudas, in its current edition, considers it acceptable though less advisable.
Is it written «motu proprio» or «motu propio»?
Motu proprio, with no preposition in front: not «de motu proprio» or «por motu proprio». The same goes for «grosso modo», which never takes «a» in front.
How do you abbreviate «número» (number) in a legal document?
n.º, with the point before the superscript letter, and n.os in the plural. «núm.» and «nro.» are also valid. The form «nº», without a point, is incorrect.
Is it written «artículo 1902» or «artículo 1.902»?
Artículo 1902. Numbers that identify an item in a series, such as an article or a law, are written without a thousands point or space.
What is the gerund of posteriority?
The gerund that expresses an action after that of the main verb, as in «abandonó el inmueble, devolviendo las llaves un mes más tarde» (left the property, returning the keys a month later). The Libro de estilo asks you to replace it with a coordinate clause: «abandonó el inmueble y devolvió las llaves un mes más tarde» (left the property and returned the keys a month later).
Is a female judge «la juez» or «la jueza»?
Both forms are valid according to the Libro de estilo de la Justicia. For «fiscal» (prosecutor), the recommended form is «la fiscal». What should not be done is to use the masculine form to refer to a woman, as in «la abogado» instead of «la abogada» (the lawyer).