Page 457 - Practical English Usage 3ed - Michael Swan, Oxford

2 I found it strange being . ..
This structure is also possible with -ing form objects.
I found it strange being in her house.
3 I would appreciate it if ...
It is used as a preparatory object for an if-clause after would appreciate. I would appreciate it ifyou would keep me informed. (NOT {W6ttltl
aP1'reeitJte i/ytJlt f;tI()lt/tl ..•)
4 owe and leave
Note the structures owe it to somebody to ... and leave it to somebody to ... We owe it to society to make our country a better place.
I'll leave it to you to decide.
448 prepositions (1): introduction
1 meanings and use
It is difficult to learn to use prepositions correctly in a foreign language. Most English prepositions have several different functions (for instance, one well- known dictionary lists eighteen main uses of at), and these may correspond to several different prepositions in another language. At the same time, different prepositions can have very similar uses (in the morning, on Monday morning, at night). Many nouns, verbs and adjectives are normally used with particular prepositions: we say the reason for, arrive at, angry with somebody, on a bus. Often the correct preposition cannot be guessed, and one has to learn the expression as a whole. In some expressions English has no preposition where one may be used in another language; in other expressions the opposite is true. For details of some difficult cases of prepositional usage, see 449-454.
2 word order
In English, prepositions can come at the ends of clauses in certain structures, especially in an informal style. For details, see 452.
What are you thinking about? She's not very easy to talk to. You're just the person I was looking for. I hate being shouted at.
3 -ing forms
When we use verbs after prepositions, we use -ing forms, not infinitives. For details, see 298, 454.
She saved money by giving up cigarettes.
When to is a preposition, it is also followed by -ing forms. (see 298.2).
I look forward to seeing you soon.
4 prepositions before conjunctions
Prepositions are sometimes dropped before conjunctions and sometimes not. For details, see 453.
I'm not certain (oj) what I'm supposed to do.
The question (oj) whether they should tum back was never discussed. ~
prepositions (1): introduction 448
page 425