Can I plug in my modems Ethernet cable to telephone line with adapter, and can I use another telephone to Ethernet adapter in other places of the house.
First what type of connection do you have? If you have DSL, then typically you can use the existing phone line that is tied together with a filter.
Your ethernet cable (out the back of your router, LAN ports) is ONLY for network. It carries nothing a phone could use.
( I do have cable modem and another VOIP provider. Since the phone lines are disabled, I did cut off the side that goes to the phone company and I do pass the phone signal through the house, so I feed the rest of the house with that using the existing phone jacks.)
"CAN I USE THE PHONE LINE WITH MY ETHERNET CABLE?"
No. Insufficient pair count. 4 pair with Ethernet, only 1 pair in a typical house jack.
"Can I plug in my modems Ethernet cable to telephone line with adapter, and can I use another telephone to Ethernet adapter in other places of the house."
No. There are some (relatively low speed) adapters that will let you use the power wiring in your house, to carry Ethernet traffic. Far faster to use WiFi however.
I can make a connection *anywhere* — I cheat. A lot.
A *lot* of newer houses (20 years or younger) have 4 or 6 pair cable behind your telephone jacks. If so, you can take two unused pairs to wire them up as a pair of Ethernet jacks.
Otherwise, you can get home phoneline networking adapters.
sure. All you need is a dial-up modem. You can run your Ethernet cable from the modem to your computer. You'll still need a phone line to go from the modem to the wall though. And the internet speed means you won't read this message until it fully loads in a couple of hours.
If the phone line is connected to the modem/router and the modem/router has an Internet connection then yes, otherwise no.
yes it is possible if you connect it with modem or router
Yes. You can use it through modem.