SEATTLE — For more than a year, Amazon searched for a second headquarters, a home to as many as 50,000 workers that would be coequal to its current home in Seattle. Instead, Amazon is closing in on deals to split what it called HQ2 into two locations, according to people briefed on the discussions. The company appears ready to move to Long Island City in Queens, according to two of the people. It is also close to a deal to move to a spot in Arlington, Virginia, just across the Potomac River from Washington, one of the people said.

Much of the process has been secret, and Amazon had local officials and real estate developers sign nondisclosure agreements during negotiations. Here is what we don’t know so far.

  • Where exactly will the two sites be?

The specific location in Long Island City is not known, but about 10 million square feet of potential office space was identified in the area, according to a third person briefed on the discussions. Amazon executives used the term “campus” to refer to the location during negotiations, another person said.

Amazon estimates 170 square feet per employee, according to a 2017 email from Amazon to a Colorado official disclosed in a public records request.

In Arlington, the plans center on Crystal City, an office area developed in the 1970s for defense contractors that largely left the area a decade ago. The developer JBG Smith acquired a portfolio of buildings a few years ago and now owns 44 percent of Crystal City, according to Rich Bradley, who was until recently the interim director of the Crystal City Business Improvement District.

Amazon could initially move into the older buildings in Crystal City, said Bradley, who was not directly involved with the bid. In September, JBG Smith backtracked on plans to convert an older office building into apartments, despite a glut of available office space in the area. Locally, the decision was seen as a sign that the space could be on hold for Amazon.

Bradley said some larger tracts nearby could be developed into new buildings over time.

“When you’d fly into National, you could see a building that says Amazon on the side,” he said, referring to Ronald Reagan Washington National Airport.

Amazon has said it wants to build up its new presence quickly next year. Crystal City has more infrastructure in place, so Amazon could add workers there faster than in Long Island City, according to a source familiar with the plans.

  • What taxpayer incentives will Amazon get?

This is a billion-dollar question — or more. While some states made their incentive packages public (New Jersey and Maryland offered more than $5 billion each), Virginia and New York have kept theirs secret.

States, cities and counties often run their own incentive programs, each with different requirements. New York state, for example, provides tax credits to employers that move to certain parts of boroughs beyond Manhattan. Many experts expect large deals like this to come with offerings that would require state legislative approval. Usually they involve little public debate. After just a 10-minute public comment period, Apple got $213 million in state and local incentives to build a data center in Iowa, according to The Des Moines Register.

New York offered potentially hundreds of millions of dollars in subsidies, according to a person briefed on the process.

While Virginia has a reputation for being business friendly, it is not known for particularly outsize incentive programs. Greg LeRoy, executive director of Good Jobs First, which tracks corporate subsidies, said he expected that the legislature would pass a larger package just for Amazon.

In New York, Amazon could also benefit — directly or indirectly — from a provision in the tax overhaul that President Donald Trump signed last year. To spur investment in “distressed” parts of America, the provision creates so-called opportunity zones, which were selected this year by governors and approved by the Treasury Department. Projects in those zones can reduce capital gains taxes and avoid those taxes entirely on profits from an investment held for more than a decade.

There are a dozen opportunity zones in Long Island City, including in several areas marked for business development.

Proposed program regulations from the Treasury Department would prevent Amazon from reaping the largest possible windfall of the tax break, because most of its business is outside the zone. But Amazon could set up a real estate company to buy land for the headquarters or surrounding buildings — and avoid any potential capital gains taxes if it ended up selling the property. Or it could lease the land from another developer that invests in the zone, insisting on more favorable leasing terms because the landlord is in line to reap opportunity zone tax benefits.

“Amazon coming, plus the opportunity zone incentive, is a huge gift to whoever owns the land in Long Island City,” said Brett Theodos, a principal research associate at the Urban Institute, a nonpartisan research group. “Now, if Amazon is a shrewd negotiator, they’re going to say: ‘We don’t have to come here. We want a piece of that.’”

  • Who is negotiating the deal?

Megadeals like this typically involve city and state officials as well as real estate developers. In New York, Amazon executives met separately with Gov. Andrew Cuomo and Mayor Bill de Blasio, according to people familiar with the process.

In Virginia, Gov. Ralph Northam, the Virginia Economic Development Partnership and Arlington County officials have been involved.

  • What is the timing?

The formal announcement could come as soon as this week or next week, according to a person briefed on the process. Much past that, and it will run into Thanksgiving, Cyber Monday and the holiday season, when Amazon wants its headlines to be about shopping, not its buildings.