`study` 作为动词，主要有以下几种形式：

一般现在时 ：`study` 的形式为 `studies` 或 `study`。

例句：`He studies in number one middle school.`

一般过去时 ：`study` 的形式为 `studied`。

例句：`She studied him for a long time.`

一般将来时 ：`study` 的形式为 `will study`。

例句：`I will study in a university in two years.`

现在进行时 ：`study` 的形式为 `is studying`、`am studying` 或 `are studying`。

例句：`We are studying maths now.`

过去进行时 ：`study` 的形式为 `was studying`、`were studying`。

`study` 作为名词，主要有以下几种形式：

复数形式 ：`studies`。

例句：`She is doing a business studies.`

第三人称单数形式 ：`studies`。

例句：`Charles and I were closeted in his study for the briefing session.`

动名词形式 ：`studying`。

例句：`She is currently doing a business studies.`

过去式 ：`studied`。

例句：`He studied hard for his exams.`

过去分词 ：`studied`。

例句：`The study room was left in a mess after they finished their studies.`

不定式形式 ：`to study`。

例句：`She decided to study abroad next year.`

现在分词形式 ：`studying`。

例句：`He left his studies to go for a walk.`

名词形式 ：`study`。

例句：`The study of history is fascinating.`

以上是 `study` 动词和名词的主要形式及其用法。