Both… and: 〜も〜ば〜も

〜も〜ば〜も lists two facts of the same kind: “there's A, and there's also B”, “both… and…”. Despite the ば, it isn't a condition. It's used to show variety (いい日もあれば悪い日もある) or to pile up two qualities or flaws.

• 人生、いいこともあれば悪いこともある。じんせい、いいこともあればわるいこともある。Life has its ups and downs.
• 彼は歌も歌えば、ダンスもする。かれはうたもうたえば、だんすもする。He sings, and he dances too.
• 名古屋のみそかつは、好きな人もいれば、苦手な人もいる。なごやのみそかつは、すきなひともいれば、にがてなひともいる。Nagoya's misokatsu — some people love it, others can't stand it.

You set two elements side by side, each followed by も: “A too…, B too…”. The first verb is in the ば-form, the second in the normal form. The ば sets no condition: it acts as a hinge, like “on the one hand…, on the other…”.

Two uses: showing variety (there's this and there's that), or piling up two things of the same kind (he sings and he dances; it's expensive and it's bad).

• 雨も降れば、風も吹く。あめもふれば、かぜもふく。It's raining, and on top of that the wind is blowing.

Verb: ば-form. い-adjective: 〜ければ. な-adjective or noun: 〜なら or 〜でもなければ (in the negative). The second verb is often the same as the first, or a verb of the same family.

• あの店は安くもなければ、おいしくもない。あのみせはやすくもなければ、おいしくもない。That restaurant is neither cheap nor good.
• あの店は値段も高ければ、サービスも悪い。あのみせはねだんもたかければ、さーびすもわるい。That shop is expensive, and the service is bad too.

The main trap: reading 歌も歌えば as “if he sings”. The double も is the signal: when you see N も 〜ば N も, it's a list. A condition wouldn't have this parallel structure.

• 安ければ買う。やすければかう。If it's cheap, I'll buy it. (condition)
• この町は海もあれば山もある。このまちはうみもあればやまもある。This town has the sea, and the mountains too. (list)

〜し〜し (N4) lines up reasons or arguments (安いし、おいしいし、よく行く). 〜も〜も is the simple list. 〜も〜ば〜も is more structured, a little more written, and often carries an idea of variety or contrast.