Spoken Contractions I: 〜てる / ちゃう / とく / なきゃ

Learners meet 〜ている, 〜てしまう, 〜ておく, and 〜なければ as full, tidy textbook forms — and then discover that in real speech almost nobody says them that way. People say 食べてる, 食べちゃった, 買っとく, 行かなきゃ. These are not slang and not corner-cutting: they are the ordinary spoken pronunciation of those grammatical forms, the way "going to" becomes "gonna" — except far more systematic and far more frequent. The real skill here is double: producing these so you don't sound bookish, and, more importantly, parsing them the instant you hear them, because subtitles, songs, and half the sentences you'll ever hear are built from them. This page teaches the reduction system; the full grammar of each underlying form lives on its own page, which I'll point to as we go.

〜てる — the reduction of 〜ている

The single most common contraction in the language: 〜ている loses its い and becomes 〜てる. After a voiced て-form (〜でいる) it becomes 〜でる.

遊んでる is 遊んでいる; 待ってて is 待っていて (the て-form of 待っている, with the い gone). This reduction is so complete that many speakers barely register the full form as spoken language at all. It applies to every meaning of ている — the ongoing action here, but equally the resultant-state and habitual meanings covered on ている overview; the casual-contraction detail is on ている → てる.

〜とく — 〜ておく compressed

〜ておく ("do in advance / for later") contracts to 〜とく; the voiced 〜でおく becomes 〜どく. Because the whole force of ておく is preparation, とく is the sound of everyday "I'll get it sorted."

やっとく is やっておく; 冷やしといた is 冷やしておいた; 読んどく is 読んでおく. The preparatory "for later" meaning is unchanged — see ておく: preparation for the full semantics. Only the sound has shrunk.

〜ちゃう / 〜じゃう — 〜てしまう, plus a layer of meaning

This is the contraction that does the most work. On the surface 〜てしまう simply becomes 〜ちゃう (voiced 〜でしまう → 〜じゃう). But 〜てしまう never meant only "do" — it always carried completion and regret, the "oops / went and did it / all done" coloring. The contraction inherits every bit of that. So 〜ちゃう is doing two jobs at once, and hearing only the shortened sound while missing the built-in attitude is the difference between decoding the form and understanding the speaker.

Notice the range. 食べちゃった can be neutral "ate it" or rueful "went and ate it all" depending on context and tone. 忘れちゃった is pure "darn, I did it." 終わらせちゃおう flips the same completion nuance into something positive — "let's just get it done and over with." That spread of neutral-completion / regret / relief is inside the form itself, inherited straight from てしまう.

The full semantics of completion-and-regret are on てしまう: completion & regret. One warning to plant now: 〜ちゃう (auxiliary, from てしまう) looks almost identical to 〜ちゃ (from ては, as in 食べちゃだめ "you mustn't eat"). They are different animals — one inflects like a verb, the other is followed by だめ/いけない — and the next page sorts them out.

〜なきゃ — 〜なければ compressed, and standing on its own

The obligation form 〜なければ ("if not…") contracts to 〜なきゃ. Its cousin 〜なくては contracts to 〜なくちゃ (same meaning, treated on なきゃ / なくちゃ).

Here is the neat part. The full obligation form is 行かなければならない or 行かなければいけない ("must go"). In casual speech the ならない/いけない tail is simply left off — 行かなきゃ alone means "I gotta go." The reduction and the ellipsis stack: 〜なければならない collapses to 〜なきゃ and then loses its own ending, so a two-word "must" survives as a single trailing なきゃ. The complete obligation paradigm is on なければならない.

The reduction map

Every contraction on this page follows the same instinct — squeeze out a syllable that the listener can restore. Here they are side by side:

Recognition is the real skill

You can get through life producing the full forms — they are perfectly grammatical, just bookish. What you cannot do is understand casual Japanese without parsing the contractions, because the contracted shape is the one people actually use. When you hear 何持ってく？ you must instantly unpack it to 何を持っていく ("what are you taking?"); when you hear 電気消しといて you must hear 消しておいて ("leave the light off for now / turn it off in advance").

持ってった is 持っていった (past of 持っていく, doubly contracted); 消しといて is 消しておいて. Train your ear to expand these on the fly, and the second page — 〜んだ / って / じゃ / し — completes the toolkit with the copula and connective reductions.

Common mistakes

Mistake 1 — Only ever producing the full 〜ている and sounding bookish. Comprehensible, but it marks you instantly as a learner reciting textbook forms.

Mistake 2 — Hearing 〜ちゃった as a flat past tense. Missing the "oops / all done" coloring means you understood the words but not the message.

Mistake 3 — Confusing 〜ちゃう (from てしまう) with 〜ちゃ (from ては). They sound alike but behave completely differently.

Mistake 4 — Using these contractions in formal or written contexts. They are spoken-casual; an essay or a keigo email wants the full forms.

Key takeaways

• 〜てる, 〜とく, 〜ちゃう, 〜なきゃ are the normal spoken pronunciation of ている, ておく, てしまう, なければ — not slang.
• Each squeezes out a syllable the listener can restore; the map above covers the voiced variants (でる, どく, じゃう) too.
• 〜ちゃう does double duty: it is a contraction and it carries てしまう's completion/regret/"oops" — hear the attitude, not just the shortened sound.
• 〜なきゃ can stand alone as "gotta," with the ならない/いけない tail dropped.
• The decisive skill is recognition — you can survive producing full forms, but you cannot understand casual speech without parsing the contractions on the fly.
• Don't carry these into formal or written registers, where the full forms belong.