您好,
第一句您和您老師都是對(duì)的.只是語法歸類不一樣而已.
1）、I thought（that）it is difficult .這是一個(gè)復(fù)合句,包括主句和從句,
（that）it is difficult為thought的賓語從句.所謂的賓語從句就是在句中作賓語的一個(gè)從句.
賓語包括動(dòng)詞賓語和介詞賓語,通常由名詞、代詞（賓格）、動(dòng)名詞、不定式、從句充當(dāng)賓語.
如
1、 He helped me .代詞me作動(dòng)詞helped的賓語
2、i went to school with Lily.名次Lily作介詞with的賓語.
3、i think （that）he is right .從句（that）he is right作動(dòng)詞think的賓語
2）I thought it difficult.這個(gè)結(jié)構(gòu)就是：賓語+賓語不足語
所謂賓語不足語：就是補(bǔ)充說明賓語的一個(gè)句子成分.
通常由形容詞、名詞、動(dòng)詞不定式、動(dòng)名詞充當(dāng)賓語補(bǔ)足語
1、I thought it difficult.形容詞difficult補(bǔ)充賓語it,作賓語補(bǔ)足語
2、we made him our monitor（班長(zhǎng)）名詞monitor補(bǔ)充賓語him,作賓語補(bǔ)足語
3、his mither made him do some cleaning.省略to的不定式,補(bǔ)充賓語him,作賓語補(bǔ)足語
第二題,您是對(duì)的.
I hope you can happy every day
這也是復(fù)合句,其中（that）you can happy every day.這個(gè)從句中情態(tài)動(dòng)詞后缺少一個(gè)動(dòng)詞原形,用be、become等系動(dòng)詞都是對(duì)的.
希望能幫到您.