Have you tried using Google (or another search engine) to resolve grammar problems? For example, students asked me to explain the following sentences from the " IELTS Writing Task 2: happiness essay " in Wednesdays lesson:
- There are some basic preconditions to achieving happiness.
- There do seem to be some common needs that we all share.
- It is no doubt true that...
If we put quotation marks ("...") around the key words, and Google them, we can look for patterns in the search results that help us to understand the grammar.
Try searching for "preconditions to achieving", then try "preconditions to being" and "preconditions to doing". The search results should show you that "preconditions to +ing" is a normal grammar pattern in English.
Now search for "there do seem to be" and "it is no doubt true that". You might find that searching for grammar patterns is more useful than learning grammar rules.