[1]"X caused Y" = X resulted in Y. X was the reason Y occurred. [2]"X are caused by Y" = instances or cases of Y can result in X. X is sometimes or generally caused by Y. [3]"X caused by Y" = incomplete sentence. This entire clause is a subject you are preparing to talk about. In other words, "X caused by Y" is a specific subset of X that satisfy the condition of having been caused by Y, and you have something to say about this specific subset. Your original sentence is effectively describing a subject, and you haven't said anything about it yet. For example: (SUBJECT) [IDEA CONCERNING SUBJECT] (MEANS/METHOD) >>(Many accidents on the roads caused by incautious drivers) can be avoided by (passing such and such a law.) What you are probably trying to do is state a simple fact, that is example [2] from above: >>"Many accidents on the roads //ARE// caused by incautious drivers." Here, (Many accidents on the roads) is made into the subject because of the verb "to be" (ARE) that comes after it. The problem in the original sentence is there is effectively NO VERB. "cause" by itself is a verb, BUT when you use it in the form of "caused by", it functions NOT as a verb, but as a simple DESCRIPTION. When you want to connect a SUBJECT with a DESCRIPTION, you have to use a verb like "TO BE". (is/are/was/etc.) Sentence 2 is grammatically correct but I wouldn't use "pierce into" unless the light was shining through holes in a curtain, cracks in some blinds, or something. If they're unobstructed, regular windows, the light would simply "shine" (past tense: "shone") into the room. Sentence 3: just put "Please" in FRONT of your request: "...please give me shoes of a larger size." It's also more natural to say "a larger size". Sentence 4: "middle of" is almost ALWAYS used with "in". You need to add "a" to "nightmare" OR make it plural. "a nightmare" is the most natural though. You use "at" for POINTS in time or space like "at midnight" or "at the midpoint of the bridge."

Many accidents on the roads [are] caused by [distracted/inattentive] drivers. The light pierced into the room through the open windows. These shoes [are to small/tight, pinch my toes], [please give me a larger size.] I woke up [in] the middle of the night because [of a/I had a] nightmare. Post this in notebook next time. It's easier to correct.