Should we take the train or fly from Madrid to Seville?

You can take the train from Madrid Atocha train station to get to Seville.
This site lists all the options on how to get there from the airport
https://www.welcomepickups.com/madrid/airport-transfer-to-atocha-train-station/

You should probably wait till you get to the train station to buy the ticket to Seville, given the possibility that your flight will not arrive at the time it was scheduled to, which would cause you to miss the train.

You could also fly from Madrid ; as long as the plane arrives on time at 7:40 am you could realistically catch a flight scheduled at 11:25 on May 6th; those flights leave from terminal 4. But it is also risky to buy this in advance and super expensive to buy a flight on the same day at the airport.

Thanks--will the fast train (AVE) tickets still be available if we wait till the same day to buy the tickets. Looks like they are about $60 now (and will we be able to understand how to buy the ticket, given that we do not speak Spanish?}

It’s a shame you can’t fly directly into Sevilla, but there are no goood connections out of either IAD or BWI to Sevilla. There is one United flight with a stop in Frankfurt, but it’s expensive.

-will the fast train (AVE) tickets still be available if we wait till the same day to buy the tickets. Looks like they are about $60 now (and will we be able to understand how to buy the ticket, given that we do not speak Spanish?}

There will not be a problem the language. Both the machine where you can buy it from and some of the agents at the station speak English, as for example when I tried to buy one speaking Spanish with an agent he spoke back in English so my travel mates understood.

Hard to say whether the train you want will be sold out. There are several fast trains a day and 21 trains in all; you may want to gamble and buy the ticket; I would book the train myself at least 4 hours after that 7:40 scheduled arrival

It looks like full price tickets are €87.40, so about €55 more for the 2 of you than buying right now (around €60). If you miss the train, that's €120 down the drain so your potential loss is €175 vs a potential savings of €55. How much of a gambler are you?

The train doesn't leave from the airport. You have to take the cercanias or metro to Atocha station and then make your way to the Sevilla train and go through security before boarding. The security is not nearly as thorough as at an airport, but it does take a couple minutes and sometimes there are lines. Spanish trains close their doors 2 minutes before departure, if you aren't on the train by then, you'll watch it pull out of the station.

Coupe things. Take the train. There is a ticket office in the airport on the lower just inside the doors next to the bus stop for the bus to the station. Don't remember the terminal but just ask at any information point. Buy you tickets there. Have never seen a line at the ticket window.

Actually, since you'll already be at the airport, it would likely be faster to fly. You'll need to account for plenty of time to get through immigration, but as long as there are regular flight schedules you can almost for sure make it to Sevilla faster. And if you missed you flight because of some delay, they'd just put you on the next one.

If you take the train, you'll have to transfer to Atocha Station and catch the next available AVE. I would not pre-purchase both because you could be delayed and because time is of the essence for you. The train ride is almost 3 hours, versus a 1 hour flight. So even accounting for some down time at the airport, the plane will be faster.

Thanks for the input! Sounds like there isn't an easy answer. My husband and I are not on the same page (I want to fly and he wants to take the train), and having more information is helpful. Thanks for sharing the info!!