如果你想表达一个人或事物变化很大，你可以使用短语 "change a lot" 或 "change significantly"。例如：

He has changed a lot since the last time I saw him. (他自上次我见他以来变化很大。)
The city has changed significantly over the past few decades. (过去几十年里，这个城市变化很大。)

你还可以使用形容词 "dramatically" 来表示变化很大。例如：

Her appearance has changed dramatically since she started wearing glasses. (自从她开始戴眼镜以来，她的外貌变化很大。)
The weather can change dramatically in this region. (这个地区的天气变化很大。)

如果你想表达一个人或事物变化很快，你可以使用短语 "change quickly" 或 "change rapidly"。例如：

The market can change quickly, so it's important to stay up-to-date. (市场变化很快，所以保持最新很重要。)
Technology is changing rapidly, and it can be difficult to keep up. (技术变化很快，很难跟上。)

此外，你还可以使用短语 "evolve" 来表示一个人或事物发生变化，特别是指长期变化。例如：

Our understanding of the universe has evolved over time. (我们对宇宙的理解随着时间的推移而发生了变化。)
The company has evolved from a small startup to a global enterprise. (这家公司已经从一个小型初创公司发展成为一家全球企业。)