1. Explain it simply
赶紧 (gǎnjǐn) means 'hurry up' or 'right away'. It presses someone to act without delay.
Word order: Subject + 赶紧 + verb phrase. 赶紧 comes after the subject and before the verb.
Use it when time is short: 你赶紧吃早饭 (hurry and eat breakfast), 你赶紧去医院 (hurry to the hospital).
Keep 赶紧 in front of the whole verb phrase - do not drop it between the verb and its object.
2. Show examples
你赶紧吃早饭。
Nǐ gǎnjǐn chī zǎofàn.
Hurry up and eat breakfast.
赶紧 sits before the verb 吃
你赶紧去医院。
Nǐ gǎnjǐn qù yīyuàn.
Hurry up and go to the hospital.
act at once, no delay
你们赶紧买机票。
Nǐmen gǎnjǐn mǎi jīpiào.
Hurry up and buy the plane tickets.
赶紧 comes before the verb 买
3. Share a tip
Keep 赶紧 before the verb - say 赶紧去医院, not 去医院赶紧.