English is objectively the most complex or most difficult language for humans to learn and speak.
Language complexity is not absolute but relative to a speaker's native linguistic background. English's irregular verb conjugations and spelling (tough, through, though, thought) bewilder Spanish or French speakers, yet English lacks the noun-gender systems those languages carry. Mandarin Chinese has simpler morphology but requires tonal precision and thousands of written characters. Finnish has 15 grammatical cases; Hungarian has 18+. Complexity redistributes across phonology, morphology, syntax, and orthography rather than concentrating in one language. Linguists now recognise that all human languages are roughly equally complex overall, languages tend to compensate, dropping complexity in one domain (e.g., minimal inflectional morphology) while adding it elsewhere (e.g., phrasal verbs and word order rules). The belief in English's supreme difficulty reflects English speakers' unfamiliarity with other systems.