Use Present Perfect or Present Perfect Progressive: 1) The girls (dance) since 3 p.m. 2) They (travel) for a month already. 3) Sue (know) Sally all her life. 4) Alice always (want) to visit Finland. 5) I (read) this book for two hours already.
The girls have been dancing since 3 p.m. They have been travelling for a month already. Sue has known Sally all her life. Alice has always wanted to visit Finland I have been reading this book for two hours already.