We all know there are certain irregular verbs which do not quite fit into the normal paradigm for forming the past tense and the past participle. In other words, they do not form the past tense by adding -ed and the past participle by adding -ed/-en. These include verbs like ‘come’: come came come; ‘buy’: buy bought bought; and ’sing’: sing sang sung. Those of us who are not native speakers probably had a hard time trying to remember all these forms.
But being merely irregular is fine, at least they look alike. There are a few words in English which may seem truly out of place. Foremost of these is the verb ‘be’: am/is/are was/were been. Its tensed forms are simply too creative if they were really created out of the base form. Inquisitive as we are, we want to ask why and how.