I. Sắp xếp 1. are waiting/ outside the door/ their children/ them for. 2. Which/ after/ "I"/ ?/ letter/ come 3. hold/ a day/ yesterday/ Nam's school/ sports.

` 1. `

` to ` Their children are waiting outside the them for.

` ⇒ ` V ` + ` are/am/is ` + ` V-ing ` + ` outside the door them for.

` 2. `

` to ` Which letter come after I ` ? `

` to ` Which ` + ` N ` + ` V ` + ` after I

` 3. `

` to ` Nam's scholl held a sports day yesterday

` ⇒ ` V ` + ` V2/ed ` + ` yesterday

` ⇒ ` hold ` ⇒ ` held