JAPANESE VERB

いたす

致す

to do, humbly

Conjugation

Tap any form to hear it. The part that changes is in colour.

Say it firstHide the forms and test yourself

now, habits, and what is to come

Form	Polite	Plain
AffirmativeI do
NegativeI don’t do

finished actions

Form	Polite	Plain
AffirmativeI did
NegativeI didn’t do

て形 · joining actions, “doing”, requests

可能形 · “can”

Form	Polite	Plain
AffirmativeI can do
NegativeI can’t do

たい形 · “want to”

Form	Polite	Plain
AffirmativeI want to do
NegativeI don’t want to do

意向形 · “let’s”, “I’ll”

Form	Polite	Plain
Let’slet’s do

条件形 · “if” and “when”

命令形 · from gentle to blunt

受身形・使役形 · “is done”, “make someone do”

Form	Polite	Plain
PassiveI am done
CausativeI make someone do

One sentence for each tense, the way people say it.

Present and future

おにもつはわたしがおもち いたします。

I'll carry your luggage.
Past

せんじつはしつれい いたしました。

I'm sorry about the other day.
Te-form

ただいま、かくにん いたして おります。

I'm checking on it right now.
Potential

もうしわけありませんが、へんこうはいたしかねます。

I'm sorry, but we're unable to make changes.
Want to

ぜひ、おてつだい いたしたい とおもいます。

I'd very much like to help.
Volitional

それはわたしが いたしましょう。

Let me do that.
Conditional

いちどおやくそく いたしたら、かならずまもります。

Once I've made a promise, I always keep it.
Commands and requests

それはわたしが いたします から、きにしないでください。

I'll take care of that, so please don't worry.
Passive and causative

ごせつめい いたした ないようは、しりょうにもかかれています。

What I explained is also written in the handout.

いたす is する said humbly of yourself: わたしがいたします; what the other person does is なさる.
どういたしまして, "you're welcome", is this verb.
To say you can't, humbly, use いたしかねます rather than いたせません, so the potential sentence shows that; the imperative and passive sentences show いたす beside another verb.

The same pattern, on other verbs: godan verb (u-verb).