No sooner

No sooner is followed by than, not when

• No sooner did she complete one project than she started working on the next.

As you can see, the adverbs hardly, scarcely and no sooner are all negative expressions. When a negative expression comes at the beginning of a sentence, we use inverted word order. That means the auxiliary verb comes before the subject.

These adverbs can also go in mid-position. In that case, we use normal word order.

• I had hardly entered the room when a strange creature ran out.
• I had scarcely solved one problem before another cropped up.