Such…as

It wasn’t such a pleasant journey as we thought it would be.
She is not such a fool as you think her to be.

No sooner … than

No sooner had she read the letter than she started crying.
No sooner had I closed the door than the telephone rang.
No sooner did I reach the station than the train steamed out.
No sooner had he seen the police than he fled.

Note that the auxiliary had or did must come immediately after no sooner. Another common mistake is to use when instead of than in these sentences.

No sooner did she utter these words than she fell unconscious. (Correct)
No sooner had she uttered these words than she fell unconscious. (Correct)
No sooner she had uttered these words than she fell unconscious. (Incorrect)
No sooner had she uttered these words when she fell unconscious. (Incorrect)

Scarcely … when/before

Scarcely had I closed the door when the telephone rang.
Scarcely had I reached the station when the train steamed out.

Note that it is wrong to use than instead of when in these sentences. Another point that needs to be noted is that had should come immediately after scarcely.

Scarcely had I stepped out of the house when it began to rain. (Correct)
Scarcely I had stepped out of the house when it began to rain. (Incorrect)
Scarcely had I stepped out of the house than it began to rain. (Incorrect)

Note that it is possible to begin these sentences with scarcely. In that case, we normally put had before scarcely.

I had scarcely stepped out of the house when it began to rain. (Correct)
I had scarcely reached the station when the train steamed out. (Correct)

Hardly when/before

Hardly had I stepped out of the house when it began to rain.
Hardly had she uttered these words before she fainted.
Hardly had I reached the station before the train steamed out.

Note that it is wrong to use than instead of when/before in these sentences.