Does "solo" take an accent? What the RAE says today

Few words have sparked as much debate in Spanish as “solo”. Some people always write it with an accent, some never add one, and some change their mind depending on the day. If you hesitate too, it is not your fault: the rule has changed several times in recent decades, and each change left a generation writing differently. Let’s settle it once and for all, with the current rule and concrete examples.

The short answer

“Solo” is written without an accent in the vast majority of cases. It does not matter whether it works as an adjective (“estoy solo en casa”, I am alone at home) or as an adverb (“solo quiero agua”, I only want water): the general rule is not to add one.

There is a single exception, and it is optional: when “solo” is an adverb (equivalent to “solamente”, only) and the sentence can be misread, the writer may add the accent to remove the ambiguity. May, not must.

A bit of history: why everyone hesitates

The confusion comes from the fact that the rule has kept evolving:

• For decades, students were taught that the adverb took an accent (“sólo” = solamente, only) and the adjective did not (“solo” = without company). If you studied before 2010, you probably learned this.
• In 2010, the RAE’s Ortografía recommended never accenting “solo”, not even in ambiguous sentences, where it suggested rephrasing.
• Since 2023, after years of debate (even among the academics themselves), the RAE adjusted the wording: the accent on the adverb is admissible when the writer perceives a risk of ambiguity, “a juicio del que escribe” (in the writer’s judgment).

The practical result: it is never obligatory, and it is only acceptable on the ambiguous adverb.

The ambiguity case, with examples

When can a sentence be ambiguous? When “solo” allows both readings at once:

Trabajo solo los domingos.

This sentence can mean two things:

1. I work without company on Sundays (adjective).
2. I work only on Sundays (adverb).

In this case, if you want the second meaning, you can write “Trabajo sólo los domingos”. But you also have a cleaner option, the one the RAE recommended in 2010: rephrase.

• Trabajo solamente los domingos.
• Los domingos trabajo sin compañía.

By contrast, in sentences like these there is no possible ambiguity and the accent would be a mistake:

• Solo quería ayudarte. (Only; nobody “wants to help you without company”.)
• Me quedé solo en la oficina. (Without company; clearly an adjective.)
• Solo faltan dos días. (Only.)

A trick so you never hesitate

If you do not want to memorize nuances, keep this two-step practical rule:

1. Always write “solo” without an accent. You will be right 99% of the time and it will never be marked as an error.
2. If when you reread the sentence you notice it can be read in two ways, replace the adverb with “solamente” or “únicamente”. The ambiguity disappears without any need for an accent.

Another useful trick: if you can replace “solo” with “solamente” and the sentence still makes sense, it is an adverb; if you can replace it with “sin compañía” (without company), it is an adjective. This same kind of substitution is used with the diacritical accent in pairs such as “tú/tu” or “él/el”.

What about “este”, “ese”, and “aquel”?

The history of the demonstratives runs parallel to that of “solo”. They used to take an accent when they were pronouns (“quiero éste”); since 2010 the recommendation is never to accent them, and since 2023 the accent is allowed only in cases of real ambiguity, which are extremely rare. In practice: always write them without an accent.

In short

Spelling changes less than it seems, but when it does it leaves doubts that last for years. The best way for these rules to stick is not to reread them, but to put them to the test: in AprendeTildes you will find interactive exercises on this and other accentuation cases, so you can practice a few minutes a day. And if you want to review the basics, start with our guide to the general rules of Spanish accentuation.