ずっと

ずっと means "the whole time", "all along": something went on without a break. It goes before the verb, and with an action that lasts it usually comes with ～ている or ～ていた.

With から, ～ている says the action started then and is still going on, which English says with "have been". It is not a plain present.

Into the future

With a wish or a promise, ずっと is "forever", "always".

"Much" in a comparison

In a comparison, ずっと is "much", "far": the gap is large.

もっと is "more" – more than now, or more than something already high. Use もっと to ask for more; ずっと only compares two things that already exist.

• × ずっと大きいのはありますか → もっと大きいのはありますか

Usage notes

These go beyond time and comparison.

A long time ago

ずっとまえ前 and ずっとむかし昔 are "a long time ago", "long before".

All the way

With a road or a direction, ずっと is "all the way".