主要 + 是 + Predicate
The word 主要 (zhǔyào) means "mainly," "primarily," or "major." It can function as an adverb modifying a verb or as an adjective modifying a noun. For example, 主要是由能源价格推动的 means "is mainly driven by energy prices."
这次涨价主要是因为原材料贵了。
Zhè cì zhǎngjià zhǔyào shì yīnwèi yuáncáiliào guì le.
This price increase is mainly because raw materials have become more expensive.
他的主要工作是负责产品设计。
Tā de zhǔyào gōngzuò shì fùzé chǎnpǐn shèjì.
His main job is to be in charge of product design.
学生们主要来自附近的几个小区。
Xuéshēngmen zhǔyào láizì fùjìn de jǐ gè xiǎoqū.
The students mainly come from several nearby residential areas.