Talking through his fourth year

When he was 3 years old, the most comments I got was "How come he is not fluent at speaking yet?".  My standard response is each child develops at his own pace and I will not compare one specific area of development with other.  Whilst he may not be expressing himself verbally clearly, he understood what was said to him.  He is exposed to 3 different languages: Malay, English and Spanish.  We use all 3 languages at home.  Some have told me that it is not a good approach because it will confuse him.  Whilst others have said that it is good to expose him to the languages.  My take:  I read a report on child development regarding communication.  The gist of it is "Learning multiple languages improves a child's brain development."
I find this to be true.  His comprehension skills is good and his cognitive skills is good.  It doesn't matter to me that he uses all 3 languages in expressing himself.  To me, it indicates that he is not thinking in a particular language to express himself but finding a way to express himself verbally that he thinks is best.  In other words, he is thinking in terms of concepts unhindered by language.
Throughout this year, I find that his verbal communications has improved markedly.  My dad used to complain when will he begin to speak as his other grandchildren and great-grandchildren were talking at an earlier age.  Now, his complaint is he has difficulty following GM's conversation because he uses all 3 languages.
He is still attending his gym classes and his physical development is good.  From small I have exposed him to many social settings so he is able to adapt well in many social environments.  He interacts well socially and is able to "make friends" easily.  I find it interesting that he communicates in the language of the setting although sometimes he does mix them.  For example, if he is in a setting where English is spoken, than he will speak in English.  When he is asked a question in Malay, he will answer in Malay.  His Spanish vocabulary is still limited but he understands it so sometimes he will respond in Malay or English mixed with Spanish.
In October I started learning the Arabic language so now I am starting to expose him to this language too.  Arabic language is more complex and pronunciation is a challenge.  I find it a challenge in learning it but I think it will be easier for him as his mind is still uncluttered and he is like a sponge, able to soak up the knowledge.
I am in the position to spend a lot of time with him and I bring him along whenever the situation permits it.  This enables him to mix socially at many levels and provides an opportunity for him to communicate verbally in many settings.  To me, it is important that he learns the social skills and expressing himself is an important skill.
To those who feel that their child is not speaking well enough or learning to speak fast enough, take a look at their holistic development.  Sometimes, some children just take a bit longer to master languages but it doesn't mean that there is something wrong in them.