The SLP's count was "about 40" Normal is 50.
<8 is a number used in a some studies as a cut-off.
My DD "failed" the 18-month speech screening (self-report on paper, not with an SLP) here, because she didn't have 8 words. (Certainly not 8 "regularly" - I don't think she had said 8 different words in her life. Nor did she use signs, nor onomatapoeia.) And she failed the 24-month screening, for lack of 2-word sentences.
Two in a row got us an SLP assessment, but she'd figured out talking by then, so passed easily.
The SLP we had said that if the child wasn't frustrated by an inability to communicate, and there were no other developmental issues, that there was unlikely to be a true expressive language delay.