Can I enter the country with a visitor visa if I have a green card?

You might be able to apply for a re-entry permit instead.

Your best bet is to enter with your green card and if a question of residence being abandoned is raised by CBP, they may admit you but schedule you to report to a deferred inspection in order to present documentation/evidence of you having maintained residence in the U.S. during your extended stay abroad.

Yes, if you are willing to abandon the green card.

It would not be smart to come in as a tourist. Technically after one year abroad, your green card is dead but if you can show circumstances beyond your control that caused you to be unable to return for part of this times, U.S. Customs and Border Protection may admit you.

Consider a returning resident visa application. Consult an immigration attorney to prepare your case, which should evidence ties to the U.S. and your intent to maintain your permanent abode in the U.S.

The safest way to proceed would be to apply for the SB-1 immigrant visa and try to qualify for returning resident status. Since you already obtained a green card your tourist visa is no longer valid.

You need a consultation appointment with an immigration attorney who can advise you about your situation.

Although your green card is considered abandoned, the CBP officer may not make an issue out of it. If the officer makes an issue about your extended absence, the abandonment of your green card, normally, he or she gives you two choices either to see an immigration judge or surrender your green card on the spot. Since you have a visa, the CBP officer, after taking the green card, may allow you in on your visitor visa.

Instead of applying for a visitor visa, you can consider SB-1 with your local U.S. Consulate to request reinstatement of your green card. Among other things, you will have to show prior ties to the U.S. or evidence of long term plans to stay in the U.S. (residence, accounts, businesses, etc.) and ideally a credible/reasonable explanation of how you did not intend to abandon your green card due to circumstances out of your control and etc.

You have a difficult situation. You certainly should apply for entry using your permanent resident card or so-called green card, assuming you had a situation that prevented your ability to travel back to the U.S. within 6 or even 12 months. In this case, you should go to the American Consulate, if at all possible, to apply for a special immigrant visa. Otherwise, you should simply present yourself and your permanent resident card, and hope that you have a lenient immigration inspector. If you have no reason to maintain your permanent resident card, then it would be better to apply for admission on your ten-year visitor visa, and explain that you had abandoned your permanent residency. But you cannot have it both ways. You are either one or the other.

You cannot use a visa. You are a resident now. Consult with an attorney.