In short

The て-form is the universal connector of Japanese: it glues clauses together (“do this, and then that”), and with ください it makes the everyday polite request 〜てください. It has no tense and no politeness of its own - the last verb of the sentence carries both. Learn its sound changes now; half the grammar in this path is built on top of it.

The rule

The て-form is not a tense. On its own it means nothing more than “and then / and so”, so it can never end a polite sentence by itself. Its job is to leave the sentence open so that something else can attach: another clause, ください, or one of a dozen auxiliaries you will meet later.

Step 1 - Find the verb group (from lesson 7): Group I (五段), Group II (一段), or the two irregulars.

Step 2 - Apply the change.

• Group II is trivial: drop る, add て. 食べる taberu -> 食べて tabete, 見る miru -> 見て mite.
• Irregulars: する suru -> して shite, 来る kuru -> 来て kite (the kanji stays, the reading moves ku -> ki).
• Group I is where the work is. The final kana decides, and there are only five outcomes:
  • う・つ・る -> って: 買う kau -> 買って katte, 待つ matsu -> 待って matte, 作る tsukuru -> 作って tsukutte
  • ぬ・ぶ・む -> んで: 死ぬ shinu -> 死んで shinde, 遊ぶ asobu -> 遊んで asonde, 飲む nomu -> 飲んで nonde
  • く -> いて: 書く kaku -> 書いて kaite
  • ぐ -> いで: 急ぐ isogu -> 急いで isoide
  • す -> して: 話す hanasu -> 話して hanashite

Note the voicing: after ん and after the い of ぐ, the て becomes で. This is pure sound, not meaning.

The one exception: 行く iku (“go”). By the く rule it should be ×行いて; the real form is 行って itte. It is the only common irregular て-form in Group I, and it collides in sound with 言って itte (“say”, from 言う) - context separates them.

Adjectives and nouns link too. An い-adjective drops い and takes くて: 安い yasui -> 安くて yasukute. いい ii (“good”) is irregular: よくて yokute. A な-adjective or a noun takes で: 静か shizuka -> 静かで shizuka de, 学生 gakusei -> 学生で gakusei de.

Step 3 - Use it. Four jobs at this level:

1. Sequence in time. V-て、V-て、V-ます: the clauses come in real chronological order, and only the final verb shows tense and politeness. 起きて、顔を洗って、出かけます (okite, kao o aratte, dekakemasu) - “I get up, wash my face, and go out.”
2. Link states or descriptions. Adj-くて／N-で + Adj/N: 大きくて、静かです (ōkikute, shizuka desu) - “big and quiet.” Both halves must point the same way - do not use て to say “cheap but bad”; contrast has its own grammar later.
3. Cause, mainly with adjectives. Adj-くて／N-で + result: 寒くて、風邪をひきました (samukute, kaze o hikimashita) - “It was cold, so I caught a cold.” The result must be an involuntary outcome - a state, a feeling, a potential, something that simply happened to you - never a deliberate act, an order or an invitation. So ×寒くて、コートを着ました is wrong: putting on a coat is a choice, and a chosen action needs から (寒いですから、コートを着ました).
4. Manner or means. V-て + main verb: バスに乗って行きます (basu ni notte ikimasu) - “I go by bus” (literally “riding a bus, I go”).

Requests: 〜てください. Attach ください kudasai straight to the て-form: 待って + ください -> 待ってください matte kudasai (“please wait”). This is the standard polite request and also the standard instruction - a teacher, a doctor and a form all use it. Because it can sound directive, there is a politeness ladder above it, ending in 〜てくださいませんか 〜te kudasaimasen ka (“would you kindly …?”). Treat that as recognition only for now.

This is a hub, not a detail. The te-form is the base for 〜ている (progressive), 〜てから (after doing), 〜てもいい (permission), 〜てしまう (completion/regret), 〜ておく, 〜てみる, 〜てあげる／てくれる／てもらう and more. Every hour spent drilling it now is repaid many times.

Negative requests (“please don’t …”) are not built from the affirmative て-form above; they are built on the ない-form, as 〜ないでください, and are covered with permission and prohibition.

Forms & patterns

Group I: the final kana decides.

Group II, the irregulars, and the Group I traps.

Adjectives and nouns.

The request ladder.

Examples

Common mistakes

• 読んて (yonte) -> 読んで (yonde) - after ん the て is voiced to で. The whole ぬ・ぶ・む group behaves this way, and so does ぐ (急いで, not ×急いて).
• 行いて (iite) -> 行って (itte) - 行く is the one く-verb that breaks the いて rule. Every other 〜く verb is regular: 書いて, 聞いて, 歩いて.
• 食べますて、寝ます。 (Tabemasute, nemasu.) -> 食べて、寝ます。 (Tabete, nemasu.) - the て-form is built on the plain verb, never on ます. Politeness lives only on the final verb of the sentence.
• 静かくて、きれいです。 (Shizukakute, kirei desu.) -> 静かで、きれいです。 (Shizuka de, kirei desu.) - くて belongs to い-adjectives only. な-adjectives and nouns link with で.
• 暑くて、窓を開けてください。 (Atsukute, mado o akete kudasai.) -> 暑いですから、窓を開けてください。 (Atsui desu kara, mado o akete kudasai.) - a くて cause clause cannot be followed by anything you choose to do - not a request, not a command, not even a plain statement of a deliberate action (×忙しくて、タクシーに乗ります). Use から instead.

Tips

• Chant the Group I changes as three blocks: う・つ・る -> って, ぬ・ぶ・む -> んで, く -> いて／ぐ -> いで／す -> して. Say them out loud until they are reflex - you will need them at speaking speed, not at thinking speed.
• The plain past form た uses exactly the same sound changes with た／だ instead of て／で: 飲んで／飲んだ, 書いて／書いた, 行って／行った. Master the て-form now and the past plain form arrives free.
• 〜てください is not the magic word “please”. It is closer to “go ahead and do it” - fine from a shop assistant or a teacher, but pushy when you are asking a favour of a superior. For favours, softer patterns are coming.
• A て-clause is tenseless: 食べて、寝ました is all past, 食べて、寝ます is all non-past. Do not try to mark tense twice - ×食べました、寝ました reads as two separate sentences, not one flow.