Inversion/Emphasis

ANSWERS 1: DID I REALISE
EXPLANATION
INVERSION => ONLY WHEN/IF/AFTER/ONCE ... + AUX + SUBJECT + VERB ...
More Examples:
Only when we had left, did the child burst into tears. V ONLY WHEN ... + AUX + SUBJECT + VERB ...
Only when did the child burst into tears we had left. X After ONLY WHEN the inversion comes in the second part of the sentence!

ANSWERS 2: WE APPRECIATE IS THE WAY
EXPLANATION
EMPHASIS (PSEUDO-CLEFT SENTENCES) => WHAT-CLAUSE + BE + (TO) + EMPHASISED WORD/PHRASE
More Examples:
What I didn't like was the end of the film. V
What she wanted was (to) take a long nap. V

ANSWERS 3: NO TIME CAN YOU USE
EXPLANATION
INVERSION => AT NO TIME + AUX/MODAL VERB + SUBJECT + MAIN VERB
More Examples:
At no time had I seen the film. V AT NO TIME + AUX/MODAL VERB + SUBJECT + MAIN VERB
At no time did Jack accept that she would come. V

ANSWERS 4: HAD SHE LEFT HOME THAN
EXPLANATION
INVERSION => NO SOONER + HAD + SUBJECT + PAST PARTICIPLE ... THAN ...
More Examples:
No sooner had they got married than they started to argue. V
No sooner had they got married when they started to argue. X NO SOONER + HAD + SUBJECT + PAST PARTICIPLE ... THAN ...

ANSWERS 5: NEITHER DOES MARY
EXPLANATION
INVERSION => NEITHER/NOR + AUX/BE + SUBJECT/PRONOUN
More Examples:
Magda didn't curl her hair. Neither/Nor did Alice. V
Magda didn't curl her hair. Neither/Nor Alice did. X NEITHER + AUX/BE + SUBJECT/PRONOUN

ANSWERS 6: ELSE HAVE I EATEN
EXPLANATION
INVERSION => NOWHERE (ELSE) + AUX/MODAL VERB + SUBJECT + MAIN VERB
More Examples:
Nowhere else will you find such nice people. NOWHERE (ELSE) + AUX/MODAL VERB + SUBJECT + MAIN VERB
Nowhere else can you buy cheaper petrol than here.