More than likely, the battery is the problem. It has enough 'juice' to keep the lights on, but not enough to turn the starter. When you 'jump' your battery from another, it gives your battery the juice it needs to turn the engine over. Have a reputable shop check the starting & charging system for you.
It could be that you have corrosion between the battery posts and the cable connectors. Look for a powdery residue that us usually whitish in color. It may not be visible between the battery post and the connector.
It may further be complicated by the use of sheet metal battery cable connectors that are difficult for many people to properly tighten. Cable connectors can become corroded over time and cause poor conduction of current across the connection from the battery and the battery cable.
Use of a battery cable anti-corrosion spray (less than $4) will go a long way to help but the connection must be clean when applied - and the connection must be tight.
Use a battery post cleaning brush (less than $4) to clean the post and the connector.
Be aware however that the Impalla does not come equipped with lead cable connectors at the battery. They are manufactured from steel that is rather thin and difficult for many shade tree mechanics to properly tighten on the battery post which leads to more corrosion and / or failed starts in the future.
If this type of corrosion is the problem, replacement of the battery, or starter can be an unnecessary and costly repair.
149.99 or 189.00 and u can do it yourself its easy 2 bolts hold it in place,1 nut holds the positive cable and a plug. it will basicly fall out into your hands after unbolting the 2 tht hold it up their. or $30 bucks at the junk yard