Modal Perfect Continuous: Extended Past Deduction (C2)

They finish each other's sentences and share private jokes nobody else gets — they ___ each other since their university days, surely.

He spots a fraudulent invoice the moment it appears in the ledger — he ___ this sort of trail for decades.

They paid for the entire house in cash, with no mortgage at all — they ___ very seriously for years.

She switches between three accents without thinking about it — she ___ in different countries for most of her childhood.

By the time the consultant ordered the scan, the symptoms ___ silently for at least six months.

His technique at 22 is already flawless — he ___ seriously since he was barely six years old.

All those late-night meetings and the suspicious string of "business trips" to the same city — they ___ in secret for years.

The reviewer named every weak query and pointed to the exact lines responsible — they ___ the platform very carefully for months.

The journalist published twenty pages of receipts, internal memos and dated emails on Sunday — she ___ this story for well over a year.

Even though they barely showed it at work, the family quietly admitted later that they ___ for him from the day he was first hospitalised.

By the time the suspects boarded the ferry, the unit already had photos, registration plates and travel patterns — they ___ them since well before the contract was signed.

Her dissertation has six hundred references and engages with sources in four languages — she ___ for years simply to assemble the bibliography.

The MRI showed three separate stress fractures in different stages of healing — he ___ on that ankle for months without telling the medical staff.

By the time the external audit landed in October, the operating losses ___ steadily for at least three quarters.

They knew every door code, every guard rotation and the precise blind spot on the south-east camera — they ___ the building for weeks.