I have had a letter from Tom.的意思?

I have had a letter from Tom.的意思? I have had a letter from tom I have had a letter from tom 提问 I have had a letter from Tom（改写句子) i have had a letter from tom .里面的had是干什么的 l have had a letter from Tom I have had a letter from Tom.这个have had 是什么句型啊? I have had a letter from Tom 变成第三人称怎么改 将句子I have had a letter from Tom.改成用He做主语 I have had a letter from Tom.第一嘅have 代表?第二had 又是什麼?从句子成分分析~ I have had a letter for TOM 这句 have 与had I have had a letter from Tom!我怎么感觉多了个have.这个句子可否帮忙分析下结构.改为第三