Error catalogue
The Spanish mistakes YabLab understands
YabLab classifies every slip in your writing against a closed taxonomy of learner errors — grounded in the annotation of the COWS-L2H and CEDEL2 learner corpora. Each entry below is a real, drillable rule: the checker spots it, explains it in your language, and helps you practice it until it is gone for good.
Spelling & word form 18
- Accent: missing tilde
- Accent: tilde not needed
- Accent: el/él, tu/tú, si/sí
- Accent on question words
- Accent moves in plural or verb form
- Spelling: b versus v
- Spelling: c, s or z
- Spelling: g versus j
- Spelling: silent h
- Spelling: ll versus y
- haber versus a ver
- hay, ahí or ay
- porque, por qué or porqué
- sino versus si no
- Word boundary: wrongly joined
- Word boundary: wrongly split
- Lowercase: nationalities, months, days
- Capitalization: sentence start
Grammar 64
- Gender: wrong article
- Gender: el agua, el águila
- Gender: exceptions to the -o/-a rule
- Plural: wrong form
- Plural: unchanged nouns
- Agreement: noun and adjective
- Agreement: determiner and noun
- Agreement: predicate adjective
- Subject–verb agreement
- Agreement with a distant subject
- ser instead of estar (state)
- estar instead of ser (identity)
- ser or estar: place versus event
- ser or estar changes the meaning
- Stem-changing verb (e→ie, o→ue)
- Irregular yo form
- Irregular preterite stem
- Irregular verb made regular
- Wrong person ending
- Preterite where the background needs imperfect
- Imperfect where a single event needs preterite
- Present perfect versus preterite
- Compound past: haber as auxiliary
- Conditional form
- Future: ir a versus simple future
- Pluperfect for an earlier past
- Subjunctive after wanting or asking
- Subjunctive after emotion
- Subjunctive after doubt or denial
- Subjunctive in time and purpose clauses
- Subjunctive in relative clauses
- Indicative after certainty
- Imperfect subjunctive form
- Conditional sentence: tense pairing
- Tense shift in the subordinate clause
- Affirmative tú imperative
- Negative imperative takes subjunctive
- usted imperative
- Direct object pronoun (lo, la, los, las)
- Indirect object pronoun (le, les)
- le instead of lo or la
- le becomes se before lo
- Doubled pronoun (a mí me…)
- Reflexive pronoun: wrong person
- Missing reflexive pronoun
- Impersonal se: verb agreement
- se for accidental events
- Irregular past participle
- Participle stays unchanged after haber
- Article with generic nouns
- Article: missing
- Article: redundant
- Body parts take the article, not a possessive
- Possessive agreement
- Ambiguous su — say de él, de ella
- Spanish requires the double negative
- Choice of negative word (nada, nadie, ningún)
- Irregular comparative (mejor, peor, mayor)
- Comparative structure (más que, más de)
- Superlative form
- Infinitive as subject, not gerund
- Gerund cannot modify a noun
- Verb periphrasis needs its preposition
- al + infinitive for "when…"
Word grammar & complementation 14
- Preposition: a versus en
- Preposition: de
- Preposition missing or redundant
- para for purpose, not por
- por for cause and exchange
- para for deadlines
- Verb governs a fixed preposition
- Adjective governs a fixed preposition
- Personal a before a human object
- Personal a not needed here
- gustar agrees with what is liked
- gustar: the person is an indirect object
- Missing obligatory object
- Redundant object or complement