Irregular verbs in English are the verbs that take different forms in past simple and past participle. Remembering these forms is one of the most difficult parts of learning English process for all learners of English. However, taking a closer look at some of the irregular verbs we can notice a pattern.
Let’s take a look at four common irregular verbs that have the letter "i" as the first vowel and it is preceded by the letter "r".
Infinitive form – ride /raɪd/, rise /raɪz/, drive /draɪv/, write /raɪt/
Past Simple – rode /roʊd/, rose /roʊz/, drove /droʊv/, wrote /roʊt/
Past Participle – ridden /ˈrɪd n/, risen /ˈrɪz ən/, driven /ˈdrɪv ən/, written /ˈrɪt n/
What we can observe here is that the letter "i" is pronounced /aɪ/ in infinitive form but it changes into letter "o" in past simple and it is pronounced /oʊ/. In past participle form the letter "i" is unchanged but it is pronounced /ɪ/.
You might say that the irregular verbs "bring", "ring", "spring", or "drink" have the first vowel "i", they are also preceded by the letter "r" but they don’t follow the same pattern as the verbs mention above. At a closer look we can observe that the letter "i" in these verbs is pronounced /ɪ/ not /aɪ/ in the infinitive form (example: drink /drɪŋk/).
We can deduce one more pattern for irregular verbs that have the first vowel pronounced /ɪ/ such as "ring", "spring", "drink", "sing" or "sink".
Infinitive form – ring /rɪŋ/, spring /sprɪŋ/, drink /drɪŋk/, sing /sɪŋ/, sink /sɪŋk/
Past Simple – rang /ræŋ/, sprang /spræŋ/, drank /dræŋk/, sang /sæŋ/, sank /sæŋk/
Past Participle – rung /rʌŋ/, sprung /sprʌŋ/, drunk /drʌŋk/, sung /sʌŋ/, sunk /sʌŋk/
Here we can see very well that the letter "i" is pronounced /ɪ/ in infinitive form. In past simple form it transforms in letter "a" and it is pronounced /æ/ like in the word "cat". In past participle it becomes the letter "u" and it is pronounced /ʌ/ as in the word "cup".
Of course, there are exceptions so I recommend you to check a list of irregular verbs to make sure you use the correct form whenever you are in doubt.