In another group of verbs, the last e in the stem turns into an i in the third person plural and in all singular persons. Beneath is a list of commmon verbs with this behavior.

to ask for; to demand; to order	pedir
to serve	servir
to repeat	repetir
to say; to tell	decir
to follow; to continue	seguir
to get; to obtain, to achieve	conseguir

e → i	Singular	Plural
First person	pido sirvo repito	pedimos servimos repetimos
Second person	pides sirves repites	pedís servís repetís
Third person	pide sirve repite	piden sirven repiten

The last three verbs in this list don't only change the e into an i, but also add a g before the o for the first person singular.

e → i & -o → -go	Singular	Plural
First person	digo sigo consigo	decimos seguimos conseguimos
Second person	dices sigues consigues	decís seguís conseguís
Third person	dice sigue consigue	dicen siguen consiguen

Note that in the first person singular of seguir and conseguir, not only a g is added, but also the u disappears.

Usages of pedir