First the good news - all new verbs in English are regular. However, that doesn't help you to learn the approximately 180 irregular verbs which do exist. Luckily some of these are extremely rare but many others are very useful and you need to know them. So how do you learn them? Some teachers think you should learn a list of them 'by heart'. Other teachers think you should not learn them at all – you will just gradually acquire them over time.