Viceidol  +  492004 Sun, 23 Mar 08 03:20 AM These leaves will have turned red by next month. This sentence is future perfect. I'm wondering if I can use other modals to replace "will".  For example: These leaves could have turned red by next month. These leaves may have turned red by next month. These leaves might have turned red by next month. These leaves should have turned red by next month. These leaves would have turned red by next month. These leaves must have turned red by next month. I think these modals aren't functioned as "future perfect". They are deducing the possiblity of the future. I'm not sure if I'm right in this concept. I hope you could help me solve my doubt. Thank you very much!    Viceidol Joined on Wed, Jul 11 2007 Taiwan Regular Member 540 Modals

	Mister Micawber  +  492037 Sun, 23 Mar 08 07:13 AM . Sorry, they don't work.  Use these: These leaves could turn red by next month. These leaves may turn red by next month. These leaves might turn red by next month. These leaves should turn red by next month. These leaves would turn red by next month, if.... These leaves must turn red by next month. Mister Micawber Joined on Wed, Aug 4 2004 Yokohama Veteran Member 30,754 'The question is,' said Humpty Dumpty, 'which is to be master-- that's all.'