楼主没有提供变化格式,以下几种答案谨供楼主选择使用.
1.A storm will come soon.
= A storm is coming soon.
= A storm is around the corner soon.
= A storm is on the/its way soon.
= A storm is approaching soon.
= There is going to be a storm soon.
= There will be a storm soon.
2.They have stayed here for weeks.
= They have been here for weeks.
= They have been/stayed here since weeks ago.
= They came/arrived/got/reached here weeks ago.
= It is weeks since they came/arrived/got/reached here.
注：/ 表示可以任意选用其一.