when ir and er are conjugated the only continuation that would be similar is yo say if you have comer and vivir
comer vivir
yo=como yo=vivo
the differences would be the meanings because just like the yo meaning i ts means you your saying what your doing for example yo vivo= i live but its not always you its could be others too just like el/ella=vive it would mean he or she live so the difference would be the meanings
i dont know if this helps