The reason for this is that success at interpreting the logical subjects of infinitives (especially in passive structures) generally correlates with overall success in English. Sample Test Following ...

The passive with modals, future and infinitive forms This is an example of a passive form. We use the passive when it is not so important to know who the agent of the action is.

'Let' takes an infinitive without to, and 'allow' takes an infinitive with to. Both can be made negative with an auxiliary verb, and allow is often used in the passive form. Form (allow in passive) ...

The idea of split infinitives, largely taught during the mid-20th century, can harm the clarity of sentences — and is mistaken about what an infinitive is in the first place.

Be to + passive infinitive is often used when giving instructions. It is noticeable always on medicine bottles and can be seen on other official notices too: To be taken three times a day after meals.