大概也許不一定用英語怎麼說

生活中很多事情不能“確定一定以及肯定”，這時候就需要說“大概可能也許不一定”了。英語中能表達這個意思的都有哪些句型呢？
　　1.用I'd say加上一個獨立分句
　　I'd say he's about ready to quit his job.
　　我想說他大概準備好辭職了。
　　t加上動詞原型　　
　　It might need some oil.
　　可能需要一些油。
　　d 加動詞原型
　　He could be in the garden.
　　他可能在花園裏。
　　4.用look like加上名詞
　　It looks like a miniature motor.
　　這東西像是個微型馬達。
　　5.用perhaps做句子的開頭
　　Perhaps he needs some time off work.
　　也許他需要一些時間休息。
　　6.用maybe開頭
　　Maybe they want to come and visit this summer.
　　也許他們今年夏天想來看看。
　　7.用It's difficult to say, but I'd guess 加上一個獨立分句
　　It's difficult to say, but I'd guess that it's used for cleaning house.
　　這很難說，不過我想這是用來清理房間的。
　　8.用I'm not really sure, but I think 加上一個獨立分句
　　I'm not really sure, but I think they enjoy hiking in the mountains.
　　我不是很確定，不過我想他們很喜歡在山裏徒步。