Error catalogue
The English mistakes YabLab understands
YabLab classifies every slip in your writing against a closed taxonomy of learner errors โ grounded in the Louvain error-tagging research. 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 7
Grammar 53
- Demonstrative determiner agreement
- Wrong possessive determiner
- Wrong quantifier
- Wrong determiner choice
- Missing or wrong definite article
- Indefinite article a or an
- Redundant article with generics
- Unnecessary Saxon genitive
- Missing Saxon genitive
- Singular instead of plural
- Plural instead of singular
- Irregular plural form
- Apostrophe in plurals
- Wrong demonstrative pronoun
- Wrong personal pronoun
- Impersonal it and there
- Missing or extra subject pronoun
- Wrong possessive pronoun
- Wrong indefinite pronoun
- Reflexive and reciprocal pronouns
- Wrong relative pronoun
- Unclear pronoun reference
- Adjective before the noun
- Order of multiple adjectives
- Adjectives have no plural
- Forming comparatives
- Comparative versus superlative
- Irregular comparatives
- Adverb placement
- Subject-verb agreement
- Third person singular -s
- Forming the past tense
- Past tense for past participle
- Base form for past participle
- -ing form instead of relative clause
- Relative clause instead of -ing
- Infinitive instead of -ing
- To-infinitive instead of -ing
- Active instead of passive
- Passive instead of active
- Present simple instead of present continuous
- Present continuous instead of present simple
- Present simple instead of present perfect
- Past simple instead of present perfect
- Present perfect instead of past simple
- Present simple instead of future
- Sequence of tenses
- Wrong modal verb
- Auxiliary be, have or do
- Missing auxiliary verb
- Semi-auxiliary verbs
- Adjective instead of adverb
- Wrong part of speech
Word grammar & complementation 12
- Adjective complement pattern
- Noun complement pattern
- Preposition complement pattern
- Verb complement pattern
- Preposition after adjective
- Preposition after adverb
- Preposition after noun
- Wrong preposition after verb
- Missing preposition after verb
- Extra preposition after verb
- Article with uncountable nouns
- Plural of uncountable nouns