表达结构上差不多，it都是形式主语。但是意思上不太一样。seems带有不是很肯定的意思。
it seems+adj+ to do与it is+adj+to do 意思是：“做……似乎/是……。” 差不多一样,it 都是作形式主语，不定式作真正主语。但它们的意思有点不同。
如：
It seems difficult to learn English well . （做某事不是很肯定难）
学好英语似乎很难。
2.It is difficult to learn English well . （做某事肯定难）
学好英语很难。
3. It seems very easy for him to finish the work.
对他来说完成这项工作似乎很容易。
4. It is very easy for him to finish the work.
对他来说完成这项工作很容易。
it‘s+adj+to do 的意思是：做某事怎么样。
Doctors think it is important to drink enough water every day.
这时候It is important to drink enough water every day是宾语从句,作think的宾语.因为think 可以形成think+ 宾语+宾语补足语。
所以此句可改成Doctors think it important to drink enough water every day。也就是少了be动词is.此时,it是形式宾语
important为宾语补足语to drink enough water every day为真正宾语。能这样用的,除了find外,常见的还有：find,believe等。
扩展资料：
it 作形式主语，主要分为下列三种情况：不定式作主语、动名词作主语 和 名词从句作主语。具体分析如下：
不定式作真正主语
主要用于下列句型：
⒈It + is/was + adj./n. (形容词或名词） +to do sth.
A. 名词作表语。主要有a pity,a pleasure,an idea等。
例如：
In fact_____it___is a hard job for the police to keep order in an important football match.
再如：It is a great pleasure to do this. 这样做多好啊。
It is a good idea to think this way. 这样考虑问题是个好办法。
除be外，其他动词也有跟名词的情况。例如：
It seems a pity to waste the food. 浪费这些食物真可惜。
It requires efforts to master a foreign language. 掌握一门外语需要种种努力。
谢谢
本回答被提问者采纳如：
1.It seems difficult to learn English well . （做某事不是很肯定难）
学好英语似乎很难。
2.It is difficult to learn English well . （做某事肯定难）
学好英语很难。
3. It seems very easy for him to finish the work.
对他来说完成这项工作似乎很容易。
4. It is very easy for him to finish the work.
对他来说完成这项工作很容易。本回答被网友采纳
两个这样用是可以的吧？
不用了，已经知道了，谢谢你
eg：my Dream is to be a teacher。
seem/appear/turn out /prove也是联系动词
eg ：he seems to be ill追答
不懂得可以追问哦。