Watford have signed Adalberto Penaranda and Abdoulaye Doucoure, but both will complete the season on loan at Granada in Spain.
Doucoure, a 23-year-old midfielder, has signed a four-and-a-half-year contract after moving from Ligue 1 side Rennes, but will switch to Granada until the summer.
Penaranda, who is 18, has also signed a four-and-a-half-year deal from Granada, but will stay at the Primera Division club until the end of the campaign.
"The Hornets have secured the permanent signing of much sought-after teenage forward Adalberto Penaranda," read a story on the club's official website.
"The 18-year-old has signed a four-and-a-half-year contract at Vicarage Road, and will remain on loan in Spain with La Liga outfit Granada CF.
"The Venezuala Under-20 international beat Lionel Messi's record in December as the youngest non-Spanish scorer of a brace in a La Liga, having become Granada's youngest-ever player in November 2015."
Penaranda was reportedly attracting the attention of Liverpool and Tottenham.
France Under-21 international Doucoure will link up with Watford in the summer.
Watford chief executive Scott Duxbury said on the club's official website: "The opportunity to sign Abdoulaye Doucoure now was one we wanted to act upon, given our long-standing interest in the player.
"He is very much part of Watford's future plans, and in the time between now and pre-season he'll be experiencing high-level competitive football in Spain."