In Acts Chapter 10 when Peter went to the House of Cornelius to preach to them, TONGUES were how he knew they had received the Holy Ghost...
as many as came with Peter, because that on the Gentiles also was poured out the gift of the Holy Ghost.
46 For they heard them speak with tongues, and magnify God. Then answered Peter,
47 Can any man forbid water, that these should not be baptized, which have received the Holy Ghost as well as we?
Tongues was for the sake of Peter and the Jews who marveled that the Gentiles received the Holy Spirit just as the Jews did.
It verified to them that the Gentiles were to be recipients of the gift of salvation by grace, just like the Jews. That it wasn't just for the Jews.
People can receive the Holy Spirit and be filled with the Holy Spirit and not speak in tongues.