Mandarin Chinese sentence structure is quite different than English or other European languages. Since the word order doesn't match, sentences which are translated word-for-word to Mandarin will be difficult to understand. You must learn to think in Mandarin Chinese when speaking the language.
Just like English, Mandarin Chinese subjects come at the beginning of the sentence.
Time expressions come immediately before or after the subject.
John yesterday went to the doctor.
Yesterday John went to the doctor.
To explain where an event happened, the place expression comes before the verb.
Mary in school met her friend.
Prepositional Phrase (with whom, to whom etc.)
These are phrases which qualify an activity. They are placed before the verb and after the place expression.
Susan yesterday at work with her friend ate lunch.
The Mandarin Chinese object has a great deal of flexibility. It is usually placed after the verb, but other possibilities include before the verb, before the subject, or even omitted. Conversational Mandarin often omits both the subject and the object when the context makes the meaning clear.
I like on the train read the newspaper.