元(もと)origin, source, base, basis, foundation, root, cause, ingredient, material, (somebody's) side, (somebody's) location, original cost (or capital, principal, etc.), (plant) root, (tree) trunk, first section of a waka, counter for blades of grass, tree trunks, etc., and for falcons (in falconry), handle (chopsticks, brush, etc.), grip

ホコリがアレルギー反応(はんのう)の元(もと)となるから、頻繁(ひんぱん)に掃除(そうじ)をしないといけない。

Since dust can cause allergic reactions, I need to clean frequently. {origin, source, base, basis, foundation, root, cause, ingredient, material, (somebody's) side, (somebody's) location, original cost (or capital, principal, etc.), (plant) root, (tree) trunk, first section of a waka, counter for blades of grass, tree trunks, etc., and for falcons (in falconry), handle (chopsticks, brush, etc.), grip}

母(はは)：「玩具(おもちゃ)で遊(あそ)んだ後(あと)は元(もと)の場所(ばしょ)に戻(もど)しなさい！」

Mother: "After playing with the toys, put them back in their original place!" {origin, source, base, basis, foundation, root, cause, ingredient, material, (somebody's) side, (somebody's) location, original cost (or capital, principal, etc.), (plant) root, (tree) trunk, first section of a waka, counter for blades of grass, tree trunks, etc., and for falcons (in falconry), handle (chopsticks, brush, etc.), grip}

タバコの不始末(ふしまつ)が火(ひ)の元(もと)となって、火災(かさい)が発生(はっせい)したそうだ。

It seems that careless handling of cigarettes led to a fire, causing a fire to occur. {origin, source, base, basis, foundation, root, cause, ingredient, material, (somebody's) side, (somebody's) location, original cost (or capital, principal, etc.), (plant) root, (tree) trunk, first section of a waka, counter for blades of grass, tree trunks, etc., and for falcons (in falconry), handle (chopsticks, brush, etc.), grip}

パンデミックの時(とき)に引(ひ)きこもったことが元(もと)で、鬱(うつ)を発症(はっしょう)したとみられています。

It is believed that isolating during the pandemic led to the onset of depression. {origin, source, base, basis, foundation, root, cause, ingredient, material, (somebody's) side, (somebody's) location, original cost (or capital, principal, etc.), (plant) root, (tree) trunk, first section of a waka, counter for blades of grass, tree trunks, etc., and for falcons (in falconry), handle (chopsticks, brush, etc.), grip}

元(もと)からこの地域(ちいき)に住(す)んでいる人(ひと)はこの地域(ちいき)のことをよく知(し)っているはずだ。

People who have lived in this region from the beginning should know a lot about this region. {origin, source, base, basis, foundation, root, cause, ingredient, material, (somebody's) side, (somebody's) location, original cost (or capital, principal, etc.), (plant) root, (tree) trunk, first section of a waka, counter for blades of grass, tree trunks, etc., and for falcons (in falconry), handle (chopsticks, brush, etc.), grip}