Sampling; Language corpus; Sprachkorpus; Datensammlung; Data collection; Textkorpus (method.) ; Text corpus (method.) ; Corpus linguistics ; BNC ; National Corpus of Polish; NKJP ; Gradience (theory of grammar) ; Continuum (theory of grammar) ; Aspect (morph.) ; Tense (morph.) ; Morphologie, kontrastive; Morphology, contrastive; Contrastive morphology ; English ; Polish