"吉他用英语怎么说" can be translated into English as "How to say guitar in English".
The word for guitar in English is "guitar". It is a noun that refers to a musical instrument with six strings, played with fingers or a pick. The guitar is commonly played in many genres of music such as rock, pop, country, and blues.
To play the guitar, one needs to learn the basic chords, scales, and techniques. Regular practice is also important to improve skills and proficiency. Many people learn to play the guitar as a hobby or as a career, and there are various resources available for lessons and tutorials.