In short

Japanese has two words for “in order to”, and they are not interchangeable. ために tame ni follows something you deliberately do (大学に入るために, “in order to get into university”); ように yō ni follows something you can only hope comes about - a potential form, a negative, or a verb with no agent (忘れないように, “so that I don’t forget”). Get the test right - controllable or not - and the rest of the lesson falls into place.

The rule

Step 1 - Both take the plain form. ために and ように are subordinate-clause endings, so the verb in front of them is plain, even when the sentence finishes politely: ×勉強しますために -> 勉強するために benkyō suru tame ni. This is the register rule from lesson 17, and it never bends. The politeness lives at the very end of the sentence: 勉強するために、日本へ来ました。

Step 2 - Ask: can the subject control this? That single question chooses the word.

• You control it - you decide to do it, you can start and stop it -> ために.
• You cannot control it - it is an ability, a state, a negative outcome, something that just happens -> ように.

大学に入るために勉強しています。 (Daigaku ni hairu tame ni benkyō shite imasu.) - I’m studying in order to get into university. Entering is a deliberate act, so ために. よく見えるように前に座りました。 (Yoku mieru yō ni mae ni suwarimashita.) - I sat at the front so that I could see well. 見える mieru (“be visible”) is not something you do on purpose, so ように.

Step 3 - Check the subjects. With ために the two clauses share one subject: the person who wants the goal is the person who acts. With ように the subject usually differs, or the “subject” is an uncontrollable outcome: 子供が読めるように、ふりがなをつけました (Kodomo ga yomeru yō ni, furigana o tsukemashita) - “I added furigana so that the children could read it.” I acted; they read.

Step 4 - Recognise the four non-volitional shapes that call for ように. With the first three, ために has no purpose reading at all:

• potentials, plus the non-volitional verbs that behave like them - 話せる, 見える, 聞こえる, 分かる (hanaseru, mieru, kikoeru, wakaru). Only 話せる is a true potential form; 見える, 聞こえる and 分かる are ordinary intransitive verbs that already mean “is visible / is audible / is understood”.
• negatives - 忘れない, 遅れない, 落とさない (wasurenai, okurenai, otosanai)
• intransitives / spontaneous events - 間に合う, 治る, 入る (ma ni au, naoru, hairu in its “it goes in” sense)
• なる with a state you cannot simply perform - 上手になる, よくなる (jōzu ni naru, yoku naru). Careful: なる is not banned from ために. When you become something by deliberately working at it, ために is the normal choice: 医者になるために、勉強しています (Isha ni naru tame ni, benkyō shite imasu) - “I’m studying in order to become a doctor.”

Step 5 - Nouns take のために. ように never attaches to a noun to express purpose - Noun + のように exists, but it is the “like a …” comparison of lesson 49, not a goal. For a noun goal or a beneficiary the pattern is Noun + の + ために: 試験のために shiken no tame ni (“for the exam”), 家族のために kazoku no tame ni (“for my family’s sake”). This second reading - “for the benefit of” - is very common and has no ように counterpart.

Step 6 - 〜ようにしてください: the polite instruction. Adding してください to a ように clause turns it into a soft, standing request - not “do it now” but “make a point of doing it”. The negative 〜ないようにしてください is the standard polite prohibition, much gentler than 〜てはいけません from lesson 30.

電気を消すようにしてください。 (Denki o kesu yō ni shite kudasai.) - Please make sure to turn the lights off. 遅れないようにしてください。 (Okurenai yō ni shite kudasai.) - Please try not to be late.

Step 7 - 〜ようになる: a change that has settled in. V-plain + ようになります reports that something is now the case which was not before. Two readings:

1. Acquired ability - and here the verb must be in the potential form: 話す -> 話せる -> 話せるようになりました hanaseru yō ni narimashita (“I’ve become able to speak”). Bare 話すようになりました means “I’ve started speaking (habitually)”, which is a different claim. This dependence on the potential (lesson 37) is the single most-missed point in the pattern.
2. A settled habit - 最近、朝走るようになりました (Saikin, asa hashiru yō ni narimashita) - “lately I’ve taken to running in the mornings.”

For the loss of an ability or habit, Japanese normally reaches for 〜なくなる rather than 〜ないようになる, from lesson 28: 食べられなくなりました taberarenaku narimashita (“I can no longer eat it”).

Step 8 - 〜ようにする: a change you are working at. Same slot, する instead of なる - so, by the logic of lesson 28, the change now has an agent. The tense matters:

• 〜ようにします - a decision taken now, one-off or from today: 明日から早く起きるようにします (Ashita kara hayaku okiru yō ni shimasu) - “from tomorrow I’ll make a point of getting up early.”
• 〜ようにしています - an ongoing practice you keep up: 毎日歩くようにしています (Mainichi aruku yō ni shite imasu) - “I make a point of walking every day.” This is the form you want when describing your habits, and the 〜ている is doing its habitual job from lesson 15.

Step 9 - Two side readings to recognise, not to drill.

• ために as a cause. After a past or uncontrollable event, ために means “because of”, not “in order to”: 雪のために新幹線が遅れました (Yuki no tame ni Shinkansen ga okuremashita) - “the Shinkansen was delayed because of snow.” It is formal and written; in speech use から／ので (lesson 21). The test is simple - snow has no goals, so the purpose reading is impossible.
• のに for purpose with an evaluation. V-plain + のに plus 便利／いい／必要だ／時間がかかる says what something is good for: この鍋は肉を煮るのに便利です (Kono nabe wa niku o niru no ni benri desu) - “this pot is handy for stewing meat.” Note this is nominalizing の + に (lesson 26), not the concessive のに of lesson 33.

Forms & patterns

What can stand in front.

The selection table - three tests. Run them in order; the first two decide almost every real sentence.

Volitional verb, non-volitional partner. Most verbs have both, and switching to the partner is how you switch words.

ようになる versus ようにする.

Examples

Common mistakes

• 日本語を勉強しますために、日本へ来ました。 (Nihongo o benkyō shimasu tame ni, Nihon e kimashita.) -> 日本語を勉強するために、日本へ来ました。 (Nihongo o benkyō suru tame ni, Nihon e kimashita.) - ために opens a subordinate clause, so the verb in front is plain. ます-forms only appear at the end of a sentence.
• 忘れないために、メモします。 (Wasurenai tame ni, memo shimasu.) -> 忘れないように、メモします。 (Wasurenai yō ni, memo shimasu.) - a negative purpose (“so as not to …”) is carried by ように; ために wants a positive, deliberate act in front of it. 〜ないために does turn up in formal writing - occasionally as a stiff “in order not to”, but often as “because … not” - so for a negative purpose in ordinary Japanese ように is the safe choice.
• 上手になるために、毎日練習しています。 (Jōzu ni naru tame ni, mainichi renshū shite imasu.) -> 上手になるように、毎日練習しています。 (Jōzu ni naru yō ni, mainichi renshū shite imasu.) - getting good at something is an outcome you hope for, not an act you can simply perform, so it takes ように. Contrast 医者になるために, where becoming a doctor is a goal you deliberately work towards and ために is right: it is the state 上手になる, not なる itself, that blocks ために.
• 子供が本を読むように、ふりがなをつけました。 (Kodomo ga hon o yomu yō ni, furigana o tsukemashita.) -> 子供が本を読めるように、ふりがなをつけました。 (Kodomo ga hon o yomeru yō ni, furigana o tsukemashita.) - you are enabling somebody else, so the clause wants the potential 読める - furigana make reading possible. Plain 読む would only say that the children read, which is not what adding furigana achieves.
• 日本語を話すようになりました。 (Nihongo o hanasu yō ni narimashita.) -> 日本語が話せるようになりました。 (Nihongo ga hanaseru yō ni narimashita.) - for an acquired ability the verb must be potential (話せる), and the potential normally marks what you can do with が rather than を. The 話す version only says you started speaking Japanese habitually.

Tips

• Two English phrases, two Japanese words. If your English is “in order to do X”, you want ために. If it is “so that X happens / so as not to”, you want ように. English blurs them; Japanese does not, and the ために／ように choice is one of the most audible A2 markers.
• Look at the verb, not at your intention. Learners try to decide by asking “do I want this?” - but you always want it, that is what purpose means. Ask instead: can I make this verb into a command? 勉強してください works, so 勉強するために. ×見えてください does not, so 見えるように.
• Effort versus result. 〜ようにしています = I am trying (the outcome is not guaranteed); 〜ようになりました = it has actually happened. Answering どうやって日本語を勉強していますか with 毎日ニュースを聞くようにしています sounds natural and modest; the なる version would be a claim about results.
• This ように is not the ようだ of “seems like”. Same word, unrelated job. 彼は疲れているように見えます (“he looks tired”) belongs to lesson 49; purpose ように is always followed by another clause saying what you did about it.