ば— The Provisional / Hypothetical Conditional

• 毎日練習すれば、上手になります。

  Mainichi renshuu sureba, jouzu ni narimasu.

  If you practice every day, you'll improve.

  練習する → 練習すれば (practicing naturally leads to improving).

• 安ければ、買います。

  Yasukereba, kaimasu.

  If it's cheap, I'll buy it.

  い-adjective: 安い → 安ければ.

• この薬を飲めば、よくなりますよ。

  Kono kusuri o nomeba, yoku narimasu yo.

  If you take this medicine, you'll get better.

  飲む → 飲めば (u-verb: -u → -eba) — taking it naturally leads to recovery.

• ・Intent restriction: If the ば-clause is an ACTION verb, the main clause generally cannot be a command, request, or 〜たい — use たら instead (✗ 東京に行けばカメラを買いたい).
• ・State exception: If the ば-clause is a state (adjective/存在), the restriction lifts: 安ければ買いたい (if it's cheap, I want to buy it) is fine.
• ・Negative form: 〜なければ (行かなければ = if you don't go).

Commonly confused with

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

• 場合は (ばあいは) — In the case of / If
• なら — The Contextual "If" (Assumption)
• たら — The versatile conditional (once / if / when)
• ても / でも — Even If / Even Though
• と — If/When (Automatic-Result Conditional)