とうとう— Finally / At last / In the end

• とうとう試験に合格した！

  Tōtō shiken ni gōkaku shita!

  I finally passed the exam!

  とうとう = at last (after long effort)

• とうとう彼女は来なかった。

  Tōtō kanojo wa konakatta.

  In the end, she didn't come.

  とうとう = ultimately (after waiting, she never showed)

• 長い間使っていた車が、とうとう動かなくなった。

  Nagai aida tsukatte ita kuruma ga, tōtō ugokanaku natta.

  The car I had used for a long time finally stopped working.

  とうとう = finally (the old car gave out at last)

• ・とうとう vs ついに: both mean "finally/at last." とうとう often suggests inevitability or resignation (negative or mixed feeling).
• ・Detail: ついに is more triumphant/dramatic.
• ・Summary: Both can be used positively and negatively in practice.

Commonly confused with

The JLPT rarely asks whether you recognise a pattern — it asks which of several similar patterns fits. These are the ones とうとう is tested against.

• あまり〜ない — Not very / Not much
• ばかり — Nothing but / Only
• きっと — Surely / Certainly / I'm sure
• 急に (きゅうに) — Suddenly / All of a sudden
• そんなに — That much / To that extent
• 全然 (ぜんぜん) — Absolutely not / Not at all / (casual: totally)
• たとえば — For example / For instance
• まず — First / First of all / To begin with