〜てみる

Verb て-form + みる

• このケーキ、食べてみる？

  このケーキ、たべてみる？

  Want to try this cake?

• 先週、一人で料理を作ってみました。

  せんしゅう、ひとりでりょうりをつくってみました。

  Last week, I tried cooking by myself.

• 昨日、あの新しいゲームをやってみた。

  きのう、あのあたらしいゲームをやってみた。

  Yesterday I tried playing that new game.

• あの時、先生に聞いてみればよかった。

  あのとき、せんせいにきいてみればよかった。

  I should have tried asking the teacher back then.

• このアプリ、便利そうだから使ってみます。

  このアプリ、べんりそうだからつかってみます。

  This app looks useful, so I'll try using it.

• 新しいカフェに行ってみませんか。

  あたらしいカフェにいってみませんか。

  Would you like to try going to the new café?

• もう一度考えてみない？

  もういちどかんがえてみない？

  Why don't you try thinking about it again?

• Writing the auxiliary with the kanji 見る instead of hiragana みる — when みる follows a て-form as this auxiliary meaning 'try', it is conventionally written in hiragana; using 見る visually suggests the literal meaning 'to see with your eyes' instead.
• Using てみる for an action you did not actually do. Like English 'I tried to ...', learners use てみました when they only meant or planned to do something: ✕ 昨日、友達に手紙を書いてみましたが、忙しくて書けませんでした. てみた says the action was really carried out (to see how it goes), so it contradicts 忙しくて書けませんでした (you never even started writing). For something you intended to do but did not do, use 〜（よ）うと思いましたが: ○ 昨日、友達に手紙を書こうと思いましたが、忙しくて書けませんでした.
• Attaching みる directly to the dictionary form instead of the て-form (writing 食べるみる instead of the correct 食べてみる).
• Assuming てみる cannot be negated, or misreading its negative forms — てみる conjugates like any other verb: 食べてみなかった means 'I didn't try eating it', and やってみないと分かりません ('you won't know unless you try') is very common. Only the negative QUESTION 〜てみない？／〜てみませんか is an invitation ('why not try...?'), not a negative statement.

〜（よ）うとする (try to / attempt to)

（よ）うとする expresses making an effort or being on the verge of doing an action, often against difficulty, and the attempt can fail: ドアを開けようとしたが、開かなかった (I tried to open the door, but it wouldn't open). てみる expresses actually carrying out an action once to see what happens, and the action is completed: ドアを開けてみたら、開いた (I tried opening the door, and it opened) — the focus is on finding out the result, not on the struggle of attempting.

〜ておく (do in advance for later benefit)

てみる describes doing an action once out of curiosity, purely to find out what happens — the focus is on trying and observing the result, with no plan for future benefit: この本、面白そうだから読んでみます (This book looks interesting, so I'll try reading it). ておく describes doing something in advance, with a purposeful, forward-looking intention to prepare for something later: 試験の前にこの本を読んでおきます (I'll read this book in advance, before the exam). Even with the same verb 読む used for a single deliberate action taken now, てみる's motivation is curiosity about an unknown result, while ておく's motivation is preparing ahead of time for a known future need.

N4 grammar and reading sections often test てみる in polite invitations (〜てみませんか, 'would you like to try...?') and in short passages about trying a new experience; listening sections use casual suggestions like 〜してみたら？ ('why not try...?'), so recognizing the tentative, exploratory nuance quickly is key.