Certainly, the issue of tongues is worth discussing because it is very, very prevalent in this day, increasingly so, and that without rule or restraint, contrary to the Word of GOD.  So, lets briefly & humbly, yet firmly examine together.
 
Note: The only biblical reference to the heavenly language of tongues is found in 1st Corinthians, that is, (the spiritual language from GOD, not the "native or mother tongues" in which the apostles spoke (in Acts) to people from different countries/region who they publicly addressed… ("And how hear we every man in our own tongue, wherein we were born?" - Acts 2:.
 
The GOD given rules/ principles re: tongues - 
1. There must always be an interpreter when someone is speaking in tongues. 1 Corinthians 14:27;
2. No more than three people are to speak in tongues in an assembly/congregation. 1 Corinthians 14:2; (humbly, not judgmentally, …i've been among people/friends all yelling in "tongues" while in prayer… no one interpreted…"If therefore the whole church be come together into one place, and all speak with tongues, and there come in those that are unlearned, or unbelievers, will they not say that ye are mad?" 1 Corinthians 14:23.  This deserves caution! (one toward another, based on the Word of GOD)… Not our way, but the LORD's way, otherwise, we are in error & must correct;
3. The gift of tongues was established by GOD primarily to bring the message of the Gospel to unbelievers, not believers. 1 Corinthians 14:22
4. The purpose of tongues was also to edify the church -1 Corinthians 14:26;
5. God distributed spiritual gifts as He saw fit. 1 Corinthians 12:11;
6. It wasn't GOD's purpose that everyone have the same spiritual gifts. 1 Corinthians 12:30; and
7. The gift of tongues is the least important spiritual gift given by The LORD 1 Corinthians 12:28.
 
"I would that ye all spake with tongues, but rather that ye prophesied [declaring the Word of GOD, from the Bible only, in truth]: for greater is he that prophesieth than he that speaketh with tongues, except he interpret, that the church may receive edifying." (1 Corinthians 14:5).
 
The value of tongues was in the substantive content, not the actual or perceived/made up experience… & without interpretation tongues was considered useless (1 Corinthians 14:6-19).
 
From the above and below, using tongues as language for personal prayer contradicts the reason why GOD gave it.  The church at Corinth (the only one in the Holy Bible in which the use of tongues was briefly documented by GOD) was already abusing it… we must be careful not to carry on in like manner re: such gifts/signs,  such is apostasy. 
 
A sign is a token of something much more phenomenal, that is, "something material or external that stands for or signifies something spiritual", "something indicating the presence or existence of something else <signs of success> <a sign of the times"…  1 Corinthians 14 shows that members of that church (not every single member apparently, but many, & thus generally), were undoubtedly more interested in the phenomenon of the sign/gift of tongues, rather than in its substance… that is the receipt of grace & mercy & eternal life in/through The Lord Jesus Christ through the preaching of the Gospel of GOD's salvation for mankind.
 
We all must be careful not to abuse spiritual gifts (tongues, miracles, signs) contrary to the Word, and to the extent that they become a real distraction away from the true message of the Gospel of our Lord Jesus Christ (Which is…
▪ "For all have sinned, and come short of the glory of God" Romans 3:23,  
▪ "For the wages of sin is death [the second death,,  of the soul]; but the gift of God is eternal life through Jesus Christ our Lord." Romans 6:23 ,… for
▪ "Neither is there salvation in any other: for there is none other name under heaven given among men, whereby we must be saved." Acts 4:12
▪ "So then faith cometh by hearing, and hearing by the word of God." Romans 10:17,  that is, the faith of, The Lord Jesus Christ (not ours). (Romans 3:22, Galatians 2:16, Galatians 2:20, Galatians 3:22, Ephesians 3:12,  Philippians 3:9, Colossians 2:12, 2 Peter 1:1, James 2:1, Revelation 14:12)
 
Another word of caution to us all (from the Word) re: messages outside of Holy Scripture that are reportedly from GOD in form of tongues & the like… The Word of God/The Holy Bible contains more than enough message(s)/revelation/Good News regarding salvation and more,  from The LORD that we can ever dream or hope to receive & understand in our lifetime (accumulated over time, "For the prophecy came not in old time by the will of man: but holy men of God spake as they were moved by the Holy Ghost" 2 Peter 1:21 & "All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness" 2 Timothy 3:16… all ending with GOD's/The Lord Jesus Christ's revelation to the apostle John in the aisle of Patmos, approx. 62 yrs. after The Lord's glorious resurrection, praise The LORD!
 
It is reasonably conceivable that no man, (or woman), especially in these days has fully understood the entire Bible/Word of GOD/Wisdom of GOD. Thus, we are cautioned to focus on the written Word of GOD only… the answers, all the answers to life are contained in the Word of GOD alone.  Once we step out, there are no guarantees of truth, and thus no "safety" regarding messages/gospel(s) we receive outside the Bible.
"Every word of God is pure: he is a shield unto them that put their trust in him. Add thou not unto his words, lest he reprove thee, and thou be found a liar." (Proverbs 30:5-6)
"For I testify unto every man that heareth the words of the prophecy of this book, If any man shall add unto these things, God shall add unto him the plagues that are written in this book."(Revelation 22:18)
 "For the word of God is quick [living], and powerful, and sharper than any twoedged sword, piercing even to the dividing asunder of soul and spirit, and of the joints and marrow, and is a discerner of the thoughts and intents of the heart." (Hebrews 4:12) 
 "Through thy precepts I get understanding: therefore I hate every false way. Thy word is a lamp unto my feet, and a light unto my path" (
 
Tongues? …. "I thank my God, I speak with tongues more than ye all:Yet in the church I had rather speak five words with my understanding, that by my voice I might teach others also, than ten thousand words in an unknown tongue."  
1 Corinthians 14:6-19
 
May The LORD bless you all!