There are three groups of verbs in Japanese to make verb-form.
Notice "i" precedes "masu".This is identified as Group
”go"ikimasu is only one irregular of group1.
You can see the forms of group1 in the "a,i,u,e,o" chart.
Notice "e" precedes "masu".This is identified as Group
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
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".