まもなく私は戻って来ます。

まもなく私は戻って来ます。

It will not be long before I come back.

まもなく私(わたし)は戻(もど)って来(き)ます。

Mamonaku watashi wa modottekimasu.

間もなく (まもなく)

soon; before long; in a short time; lacking time to ...; without time to ...

私 (わたし、わたくし)

I; me; private affairs; personal matter; secrecy; selfishness

は (は)

topic marker particle; indicates contrast with another option (stated or unstated); adds emphasis

戻る (もどる)

to turn back (e.g. half-way); to return; to go back; to recover (e.g. something lost); to be returned; to rebound; to spring back

Readings: シ、わたくし、わたし

Meanings: private, I, me

Readings: レイ、もど.す、もど.る

Meanings: re-, return, revert, resume, restore, go backwards

Readings: ライ、タイ、く.る、きた.る、きた.す、き.たす、き.たる、き、こ

Meanings: come, due, next, cause, become