The adverb ずっと has two primary meanings in Japanese. The first is that something keeps going in a constant state, without ever stopping/resting, and the second is to emphasize an amount of something. We will examine the first meaning in this lesson.
To use ずっと, add it to the beginning of the phrase that you want to highlight as being ongoing.

• ずっとゲームをしないでたまには勉強（べんきょう）もする。
  Instead of continuously gaming, I occasionally also study.
• ずっと立（た）ってたから足（あし）が痛（いた）い。
  I was standing the whole time, so my feet hurt.

Alternatively, ずっと can be used after から, to express that something has been continuing ‘ever since’ some specific event/point in time.

• 昨日（きのう）からずっと寝（ね）てないからメチャ眠（ねむ）い。
  I haven't slept at all since yesterday, so I am extremely tired.
• 朝（あさ）からずっと何（なに）も食（た）べていないからお腹（なか）が空（す）いたよ。
  I haven't eaten anything at all since morning, so I am hungry.