basarse en
verbCEFR B2
What does “basarse en” mean in English?
to be based on, to rely on
to be based on, to rely on (basarse en + noun — identifying the evidential foundation of an argument)
Example sentences
Sus conclusiones se basan en una muestra demasiado pequeña para ser representativa de la población general.
Their conclusions are based on a sample too small to be representative of the general population.
El plan se basa en la premisa de que el consumo seguirá creciendo al mismo ritmo, lo cual no está garantizado.
The plan is based on the premise that consumption will continue growing at the same rate, which is not guaranteed.
Para que un argumento sea sólido, debe basarse en hechos verificables, no en opiniones presentadas como certezas.
For an argument to be sound, it must be based on verifiable facts, not on opinions presented as certainties.
How to use it
Basarse en ('to be based on', 'to rely on') is the standard verb phrase for identifying the evidential foundation of an argument. Pattern: basarse en + noun ('el argumento se basa en datos sólidos') or basarse en que + indicative ('se basa en que los costes han bajado'). The reflexive pronoun is obligatory. At B2 it is used both to describe what an argument rests on and to critique the foundations: 'el argumento se basa en una premisa cuestionable'. Essential for evaluating the quality of evidence in debate.
Common mistake
Basarse en requires the reflexive pronoun (se basa en, me baso en) — *'baso en datos' is ungrammatical. Don't confuse with apoyarse en (to lean on / to draw support from, slightly more metaphorical) — both are acceptable but basarse en is the more neutral academic choice. The construction 'basar el argumento en X' (transitive, no reflexive) is also possible: 'basa su argumento en datos sólidos'. Both forms are correct; the reflexive intransitive is more common in academic writing.