Most English learners are well aware of the pattern -ay/-aid of irregular English verbs. However, this is more the exception than the rule. There are basically only 3 verbs that follow the pattern:
say – said – said, pronounced /sɛd/
pay – paid – paid, pronounced /peɪd/
The only other verbs that follow the pattern are those derived from these by adding a prefix:
say – gainsay, unsay
pay – overpay, prepay, repay
* “relay” is irregular only in the sense of re-lay (“lay again”). In the sense of “receive and send on information”, it is regular, e.g. “the programme was relayed by satellite”.
All other verbs ending with “ay” are regular, for example:
play – played – played
stay – stayed – stayed
[... and many others]