Substituting a letter F for a letter B?

[Katymac]

A little boy I know does this - he is 3 and a half, but only sometimes

How can I help him to say B without nagging?

So we have fread, fead, fee,

but butter, blue

Any ideas?

[PotatoOfDoom]

What about I-Spy for words he has trouble with and when he says them his way just repeat with yes thats a [correct way]?
I don't know if that'll help but maybe if he continuously hears the right pronunciation he'll pick up

Also making the b sound into a balloon might ve fun?

[EffiePerine]

What about drawing pictures? This is Fred, this is bread etc.

[Katymac]

I might try some of these

(I'm not sure my pictures are up to it tho')

[christywhisty]

I was told by speach therapist, just to make a comment back and put a lot of emphasis on saying the word correctly
ie in my son's case it was t's instead of c's

if son said
"look at the tat"

I would have to say back

" yes that is a lovely cat "

[gillhowe]

Apparently i used to substitute f's for c's - my mum still laughs about me saying 'cooked carrots'

[KTeePee]

My ds is the same age and substitutes d for g (says dirl instead of girl eg). Some words he always says the wrong way, others he always says correctly. I am keeping an eye on it but assume he will grow out of it in the next year or so (and obviously always say it correctly back to him)