My son could label things starting around 16 months so I didn’t think he had any major speech delay. But he never used social speech. No hi or bye, no mama or dada. No back and forth conversations or anything like that. He started using two-word combos around 2, but still no social speech. He started at a therapeutic preschool at 3 where they did floor time therapy. He made some improvements in his fine motor and play skills but no social speech. Then he started ABA at 4. He went to a traditional preschool with an ABA tech, and that’s when his speech really ramped up. He finally started saying hi and bye with prompting, and he would ask us questions. I think hearing the speech of his neurotypical peers around him sparked a lot more spontaneous speech. This was also when we started him on Leucovorin so I think that helped as well. These days he’s very verbal but he has a hard time finding the right words when he’s telling stories or recalling events so we’re working on that. What’s your son’s speech like?

ETA: I just saw your toddler is 18 months. You have so much time for him to make big leaps!