1. In this case it does not matter whether you say 'started' or 'starting.' 2. In this case 'which' sounds slightly more formal, but both are correct. 3. Here it depends on your exact meaning. If you leave out the comma, then you can use either word (though 'which' sounds slightly more formal) and the speaker is not talking about changes of this rate which would NOT cause the buyer a loss. Such changes may exist, but are not the point. With the comma included, you should use 'which,' not 'that,' and the speaker is saying that ALL changes of this rate would cause the buyer a loss. 4. Here there is a difference in the emphasis, rather than the meaning. ① focuses on the terrible noise she heard, and also mentions that she was frightened by it. ② focuses on her fright, and also mentions that hearing a terrible noise caused it. The difference is which piece of information is more important. 5. 'Had gone' would require that you start a new sentence and restate the subject: "The English man vanished too. He had gone (or 'Had he gone' if this is a question) to find the Alchemist." 6. 'Kindle' would be correct if this were a complete sentence on its own (in which case you would leave out the comma). But in the context of the rest of the sentence (as quoted in a comment to someone else's answer), it really has to be 'kindling' (or possibly 'kindled,' though that does not sound as poetic, since the other two 'ing' words in the sentence cannot be changed to 'ed'). 7. No, you cannot use 'citing' unless you say 'are citing,' but 'cite' sounds better than 'are citing.' If you want to restate the subject, you have to break the sentence in two, like this: "In the California court papers, Stefan Bofanovich and Dakota Speas cite loss of value and loss of use as reasons for compensation. They (or 'the lawyers') claim that Iphone owners never consented to the interference." As two sentences, it is easier to read, which probably makes it a good idea, but that is up to you.

Hi For number 1 to 4, it's interchangeable and you can use both of them. But actually I can't understand number 5. And about number 6, I don't think that it's a complete sentence. so you should use Kindle instead of kindling. Because when you use kindling, you can't recognize what the tense is. Or you can say kindling by using one "are" before that.

This question is about "relative clauses" (in case you want to search for further information). In your examples, the use of a comma and “which” is appropriate for introducing a non-restrictive (also known as “non-defining”) relative clause. On the other hand, the lack of a comma would indicate a defining relative clause. With a defining relative clause, we can still use “which,” but “that” makes it clearer that the clause is “restrictive / defining.” “That” cannot be used to introduce a non-defining relative clause. Examples: Restrictive / Defining: Any change of this rate that (or “which”) would cause the buyer a loss is prohibited. The above sentence is talking only about changes that would cause the buyer a loss. Changes that would not cause the buyer a loss are not covered by the sentence. The relative clause defines exactly what kind of rate change we are talking about. Any change of this rate, which (we cannot use “that”) would cause the buyer a loss, is prohibited. The above sentence is saying that any change of this rate is prohibited, and by the way, such a change will indeed cause the buyer a loss. In this case, the relative clause is just giving us extra information that we may probably know already.