Hi all. I've just returned from my LO's 1 year check up and all was well. However, the HV commented at the end of the appointment that my other son, who turns 3 next week, wasn't speaking very well. She observed this while he babbled on in the background during the appointment. She said his vocabulary was great, and his sentences fine, but she was struggling to understand a lot of what he was saying as he uses a lot of letter replacements. I assumed it was normal for his age but HV wants to refer him to a speech therapist. Should I be worried? Thanks in advance x