How many words should a 17 month old boy say at that age? My baby can only say a few words like papa, mama, bird, etc. My daughter was talking much more at that age.

Just as what everyone is saying, every baby develops differently. In general, language skills start developing between the ages of one and two. Any form of communications, such as babbling, pointing to an object, responding to your comments, indicates that he/she is beginning to understand what is said to him/her (even though he/she is not using actual words to communicate with you). My nephew only started talking (in languages that we could understand) at around 15 months. Prior to that, it was clear that he could understand us and was blabbering in his own baby language, but he just refused to “converse” with us. He respond to us calling his name by looking over but just refuse to answer or even call his parents. Now, however, at almost four years of age, we can’t get him to stop talking. ;p Don't be too worried. He is probably learning from your conversations right now. Toddlers are always observing and learning from the things happening around them.