My favourite sport is swimming.为什么要用swimming

Swimming is my favourite sport.\uff08\u6539\u4e3a\u540c\u610f\u53e5\uff09

I like swimming _best_____ of all

\u5982\u679c\u60a8\u8ba4\u53ef\u6211\u7684\u7b54\u6848\uff0c\u8bf7\u70b9\u51fb\u4e0b\u9762\u7684\u201c\u9009\u4e3a\u6ee1\u610f\u7b54\u6848\u201d\u6309\u94ae\uff0c\u8c22\u8c22\uff01

My favourite sport is swimming\u6539\u540c\u610f\u53e5 I\uff08 like \uff09swimming\uff08best \uff09

is 是谓动词，而swim是动词（V），
而谓动词后面的动词必须是V+ing形式，
所以swim要加ing 。而swim以重读闭音节,并且词尾只有一个辅音字母,所以要双写m再加ing
这是英语中非常常见的用法 一定要掌握哦，
希望对你有帮助。

因为sport是动词，所以后面的词也要用动词。swim是名词，所以要变成动词+ing形式变成名词。

swim 是动词
而is后面跟的需要是名词
一般可以把动词加上ing来表示名词（也叫动名词）
如把swim变成swimming就可以当名词使用了

swim 是动词 so you need to use swimming or dont use is

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