Hi Alisa, You can definitely use such adverbs in both positions. Miriam has brilliantly pointed out that we have to be discerning with the position of these words if they may give rise to ambiguity. I would like to add that "yesterday" and "tomorrow" should be used at the end of the sentence in interrogative sentences. Example: Are you coming to work tomorrow? (correct) Tomorrow, are you coming to work? (incorrect) "Yesterday" can also be used in positions other than the beginning or the end of a sentence. Example: There was a snowstorm yesterday morning. (correct) Yesterday, there was a snowstorm morning. (incorrect) There was a snowstorm morning yesterday. (incorrect) In this case, however, "yesterday" is written before "morning" as an attributive adjective instead of an adverb of time. (As an adjective, it describes the day that immediately precedes today.) I hope this helps you.

I think Miriam's examples are all equally clear - it doesn't matter where you place tomorrow from that perspective. There is a difference.of emphasis: you can focus on the time by putting it at the end, which sounds odd, but makes sense with some examples: Focus on actions: A What are you doing tomorrow? B Tomorrow I have an appointment with the doctor. Focus on time: C When will you get that leg fixed? D I have an appointment with the doctor tomorrow. There is an alternative answer to C formed of two sentences, don't confuse it with B: Tomorrow. I have an appointment with the doctor.

Either is fine if the sentence is short. For example, you could say either "Yesterday I went to the store," or "I went to the store yesterday." Similarly, you could say either "Tomorrow, I will go to the store," or "I will go to the store tomorrow." If you are describing several actions that you took yesterday, it is a little clearer to put "yesterday" at the beginning of the sentence. For example: "Yesterday, I went to the city, saw my friend, and bought a couple books." Similarly, it might be a little better to put "tomorrow" at the beginning of the following sentence: "Tomorrow, I will go to the city, see my friend, and buy a couple books." That way, it is clear that each of these actions in the sentence will take place tomorrow.