I am reading a book now. ☊ 
Hiện tại tôi đang đọc một quyển sách. ☊ Continuous like: OK now → →
certain of sth/of doing sth: If you want to be certain of getting a ticket, book now. ☊ certain ☊
Don't look now, but there's someone staring at you! ☊ look ☊
Book now and avoid the last-minute rush. ☊ rush ☊