There are three groups of verbs in Japanese to make verb-form.
Group 1
Notice "i" precedes "masu".This is identified as Group
1
”go"ikimasu is only one irregular of group1.
You can see the forms of group1 in the "a,i,u,e,o" chart.
Group 2
Notice "e" precedes "masu".This is identified as Group
2.
Some of verbs in Group2 have "i" like ones in Group 1. But they
are exceptions and a few to remember. Here are the verbs that the biginers
should remember.
get up おきます/ resemble にています/take a shower シャワーをあびます/ be able to できます/put
on きます/ betired of あきます/get off おります/ look at みます/be います/ borrow かります/fall down/fail
おちます/ try(valiantly) こころみます/past すぎます/ ashamed はじます
Irregular Irregular verbs are only two, "shimasu" and "kimasu".