An offer MUST be presented in writing in order to be legal. A verbal agreement means nothing. Now, a buyer's agent can verbally inform the seller's agent that an offer is coming so that they know to expect it. But a written offer must follow.
When an "Agreement of Sale" is written, not only does it show the price offered to the seller, it also includes dates for deadlines, such as response dates, mortgage commitment dates, inspection dates, etc. The "Agreement of Sale" also has financing information, whether or not the various inspections are waived, contingencies, etc.
The offer is officially executed once both parties have signed and approved the "Agreement of Sale" and each are aware the the offer has been accepted.
I hope this information clears things up.
Brigita McKelvie, REALTOR, e-PRO, GRI
Residential, Rural and Horse Properties
Keller Williams Real Estate, Bethlehem, PA
Office: 610-867-8888 Direct: 610-393-9424