现在完成时haven't clean还是haven't cleaned?

现在完成时haven't clean还是haven't cleaned? we have to clean the classroom改为否定句是加don't还是直接改成haven't Haven't you got……是have got拥有的意思?还是现在完成时? 现在完成时的反义疑问句yuo have read the book反义疑问句用haven't you 还是don't you 现在完成时还是过去完成时?I happened to meet him in the street yesterday.We ____ each other for a long time.(haven't seen or hadn't seen) 现在完成时的否定句中haven't后用动词的什么式?明要交.是一般过去式还是过去分词,还是用原形? 现在完成时当没有时间段时能用非延续性动词吗比如:I' haven't dicided yet.中的decided是什么动词啊.是非延续性动词还是延续性动词呢?现在完成时一定要用非延续性动词吗? Carol and John hsn't/haven't found them?,该用hasn't还是haven't haven't got enough money to pay for that car为什么要用现在完成时 We haven't come to a conclusion yet.这个句子是现在完成时吗? I haven't seen you for a long time 是什么时态 不是现在完成时吗? We are leaving tomorrow and i haven't even started packing yet后面为什么用现在完成时? haven't. You will never guess who Imet today.My old teacher!We______for20 years!Haven't met/Hadn't met ...You will never guess who Imet today.My old teacher!We______for20 years!Haven't met/Hadn't met该用现在完成时还是过去完成时?个人以为用 I wonder if it's because I haven't been able to be outdoors for so longI haven't been 是什么时态 现在完成时被动语态吗? I haven’t finished my homework today.I haven’t finished my homework now.today,now可以和现在完成时连用吗? 现在完成时否定I haven't seen it从来没有看见它I hadn't noticed 怎么一个个have 一个用had i haven't failed.i didn't fail.区别.,.第一个 为什么会用现在完成时 想表达?