も〜ば〜も details
Examples
both X and Y — one subject shown to have two properties or do two things, listed as a pair
この町には古い寺もあれば、新しい美術館もある。
kono machi ni wa furui tera mo areba, atarashii bijutsukan mo aru.
This town has old temples, and it has a new art museum as well. neutral
あの店、値段も安ければ味もいいんだよ。
ano mise, nedan mo yasukereba aji mo ii n da yo.
That place is cheap, and the food's good too. casual
この計画には、費用の問題もあれば、住民の理解という課題もございます。
kono keikaku ni wa, hiyou no mondai mo areba, juumin no rikai to iu kadai mo gozaimasu.
This plan has a cost problem, and it also has the challenge of winning residents over. formal
some are X, others are Y — the same frame spread over a group, showing how far its members differ
世の中には、猫が好きな人もいれば、苦手な人もいるからね。
yo no naka ni wa, neko ga suki na hito mo ireba, nigate na hito mo iru kara ne.
In this world there are people who love cats and people who can't stand them, you know. casual
留学生の中には、日本語がとても上手な人もいれば、まだ挨拶しかできない人もいます。
ryuugakusei no naka ni wa, nihongo ga totemo jouzu na hito mo ireba, mada aisatsu shika dekinai hito mo imasu.
Among the international students, some speak Japanese very well and others can still only manage a greeting. neutral
Formation
AもV（ば形）、BもV（時間もかかれば費用もかかる）attaches to noun phrase (schematic)Aもい-adj（〜ければ）、Bもい-adj（値段も安ければ味もいい）attaches to noun phrase (schematic)
Notes
the final predicate carries tense (時間もかかれば費用も
かかった). Nouns and な-adjectives join with なら or であれば, never ×学生もば.
Related patterns
Similar
し marks its clause as grounds and may stand on one clause with the rest implied (安いし、…); も〜ば〜も marks no clause as grounds and requires every member to carry も, so it can never stop after the first half.
だけでなく ranks its two halves — the second is the addition the sentence is really about, which is why さえ／まで so often lands on it; も〜ば〜も weights the two equally and takes no such escalator.
も〜ば〜も presents its members as a deliberate balanced pair, each asserted in its own right; やら〜やら presents a disorderly heap whose members merely stand in for more, which is why it so often trails into で as the cause of the state that follows.
Lookalikes
Both double a predicate around ば, but ば〜ほど repeats the SAME word to build one rising scale (読めば読むほど) while も〜ば〜も pairs two DIFFERENT items each marked with も and builds no scale — the second も is what kills the proportional reading.