1. It was certain he had learnt the bad language at school.
2. Surely, some of them understand Swedish.
3. It is certain the woman works for the police.
4. It sticks out a mile Dave was in love with Muriel.
5. Mr Higgins had problems with his memory, for sure.
19wiki19
1..... he must have learnt... 2... them must understand. ... 3....woman must work.... 4...Dave must have been in love.... 5....higgins must have had problems...