You have someone try to start it while you look at it. If it jiggles, Then you know it is too loose but if it dosent, then it is just your car battery
Check for loose or corroded battery cables Check for loose connection at starter or ground
Dead battery, corroded or loose battery or starter cables, defective starter or starter solenoid, loose ground connection.
Check the battery for corrosion or loose connection.
The problem is not in the starter. Check the starter solenoid/relay switch or look for a loose battery cable connection.
Check all wires for loose or corroded fittings. A loose or corroded connection can work one day and not the next. My first guess would be the wire to the starter solenoid is loose.
Loose connection? Bad starter (flat spot)? Bad starter solenoid?
If the wire is loose at a connection, find a wrench that will fit it and tighten it.
the starter may not be good or the connection on the starter may be loose
Defective starter or weak battery. Can also be a loose connection at the starter.
load check the battery if not that clean the starter,clean the housing where the starter mount's,clean the battery connection's, do a voltage drop and chek 4 unwanted resistance if you cant do that take it to a shop and leave it to the pro's
Seized Engine? Loose or corroded battery cables? Loose connection at starter or solenoid? Bad starter solenoid Bad starter? Bad neutral safety switch?
Check for a loose or corroded battery cable Check for a weak battery Check for loose wire on starter or solenoid Dead spot on starter?