This is a question about changing positions on the finger board with the left hand when readying music. I know that all the notes can be played in the 1st position.
I am working with the 1st, 2nd, 3rd, 4th, and 5th position. How do you know when it is time to change position. Example: if you are playing in the 1st position... what in the
music tells you to drop down to the 3rd position and continue playing? I know where all the notes are in the 5 positions, I just do not know when to shift positions as I am learning
music.
Thank you,

There is really no wrong, or right spot to shift..

Generally its easiest to shift when you have an open note, or are shifting from third finger to first finger.

And shifting isn't just for playing higher on the E string. Sometimes its easier to play on the lower strings in a higher position for example if you going from notes above A on the E string and lower notes quickly (when shifting would be hard) or a lot of times if I am playing like, half/whole note A's i will use 2nd finger on the D string instead of open and add some vibrato etc etc.

But there is nothing in the music that tells you. There are many ways to that you can have as fingerings for passages, but especially in harder music, there are ways that are easier than others. Just try different things until you have ones that sound good and are easiest for you.

Hope that made some sense

Thank you for your reply. That does help and makes a lot of sense.

Also, in some pieces there is a little III or I or IV or V...although i have only seen III, and I. The rest is vanished. i miss it...

But seriously, in all the fifth position pieces i have seen or played, i do not see a III or V or anything in between. Here's a tip -- utilize your strengths. Go through the music, and find good places for shifting. Then play it through. Does it sound right? If not, you can adjust the fingering, such as maybe sliding earlier and playing the same notes over again until you get it right. OPEN STRINGS ARE GREAT FOR SHIFTING. (thank you person before me)

Thanks for your reply. Us violin people need to stick together.