Matthew 9:18

Strongs #G2980 λαλέω, laleó,  to chatter, chirp, emit a sound, or produce musical sounds.

This word is used nearly 300 times in the NT, way more extensively than in classical Greek literature, and it is not without reason. The normal word for speak/say, is legó #G3004 which is found about 2,267 times. 

1. Primary Meanings: Chattering, Babbling

• Chatting/talking:

  • "ἕπου ... καὶ μὴ λάλει" (Come along and don't chatter), from Aristophanes' Ecclesiazusae 1058.
  • "λαλῶν ἐν ταῖς ὁδοῖς σεαυτῷ" (Talking to yourself on the road), from Aristophanes' Knights 348.

• Sounds of Birds:

  • Refers to birds chirping or twittering.

• Music:

  • "αὐλῷ λαλέω" (I play the flute), from Theocritus, Idylls 20.29.
  • "ἡ φωνή ... ὡς σάλπιγγος λαλούσης" (The sound as of a trumpet blaring), from the New Testament, Revelation 4:1.
  • "ὅτε ἐλάλησαν αἱ ἑπτὰ βρονταί" (When the seven thunders chattered), from the New Testament, Revelation 10:4.

2. Later Meanings:

• General Talk or Prattle:

  • "λαλῆσαι οὔπω δυνάμενον ἃ πάσχει" (Not yet able to say what ails him), from Plato's Axiochus 366d.

It was assumed that the NT was using this word in a "higher religious" sense, and thus was never translated in its original, primary sense.

"οὐ γὰρ ὑμεῖς ἐστε οἱ λαλοῦντες ἀλλὰ τὸ πνευμα" (For it is not you who chatters, but the Spirit), from the New Testament, Matthew 10:20.

"λαλεῖν ἀπό τινος" (To chatter on behalf of someone), from the New Testament, 2 Peter 1:21.

The verb "λαλέω" primarily means to chatter, prattle, or babble, often used in contexts involving informal or non-articulate sounds, such as those made by birds, music, or nature. The New Testament makes extensive use of this word as opposed to the normal word for speaking.