First-person consonant alternations
Recognise that the я form may have a different stem consonant from the rest of the Type II paradigm.
Many Type II verbs alternate specifically in the я form, as in любить → люблю beside любишь. These are lexical paradigm facts.
- Do not force a single modern spelling rule to generate every alternation.
- Store the я form with the infinitive for non-transparent verbs.
- Other person forms may preserve the unalternated consonant.
Mini-check
How should люблю beside любишь be learned?
Why this happens
Historical palatalisation, an older pattern in which a consonant changed near a front-vowel or y-like sound, helps explain many alternations. You do not need that history to form the verb: learn its verified principal forms.