Should I be worried for his Speech

It's important to remember that not every child is the same. Children reach milestones at different ages.  Here is a chart to roughly understand their development/milestone. Birth to 5 mth: coos, vocalizes pleasures and displeasures sounds differently ( laughs, giggles, cries and fussers) Makes noise when talked to. 6-11 mths: Understands "no-no" Babbles (says "ba-ba-ba") Says "ma-ma" or "da-da" without meaning Tries to communicate by actions or gestures Tries to repeat your sounds Says first word 12-17mths: Answers simple questions nonverbally Says 2 to 3 words to label a person or object (pronunciation may not be clear) Tries to imitate simple words Vocabulary of four to 6 words. 18-23mths: Vocabulary of 50 words, pronunciation is often unclear Asks for common foods by name Makes animal sounds, such as "moo" Starting to combine words, such as "more milk" Begins to use pronouns, such as "mine" Uses 2-word phrases 2-3yrs: Knows some spatial concepts, such as "in" or "on" Knows pronouns, such as "you," "me" or "her" Knows descriptive words, such as "big" or "happy" Uses 3-word sentences Speech is becoming more accurate, but may still leave off ending sounds. Strangers may not be able to understand much of what is said. Answers simple questions Begins to use more pronouns, such as "you" or "I" Uses question inflection to ask for something, such as "my ball?" Begins to use plurals, such as "shoes" or "socks" and regular past tense verbs, such as "jumped" 3-4 yrs: Groups objects, such as foods or clothes Identifies colors Uses most speech sounds, but may distort some of the more difficult sounds, such as l, r, s, sh, ch, y, v, z, th. These sounds may not be fully mastered until age 7 or 8. Uses consonants in the beginning, middle, and ends of words. Some of the more difficult consonants may be distorted, but attempts to say them Strangers are able to understand much of what is said Able to describe the use of objects, such as "fork" or "car" Has fun with language; enjoys poems and recognizes language absurdities, such as, "Is that an elephant on your head?" Expresses ideas and feelings rather than just talking about the world around him or her Uses verbs that end in "ing," such as "walking" or "talking" Answers simple questions, such as "What do you do when you are hungry?" Repeats sentences 4-5yrs: Understands spatial concepts, such as "behind" or "next to" Understands complex questions Speech is understandable, but makes mistakes pronouncing long, difficult, or complex words, such as "hippopotamus" Uses some irregular past tense verbs, such as "ran" or "fell" Describes how to do things, such as painting a picture Lists items that belong in a category, such as animals or vehicles Answers "why" questions 5 years Understands time sequences (for example, what happened first, second, or third) Carries out a series of 3 directions Understands rhyming Engages in conversation Sentences can be 8 or more words in length Uses compound and complex sentences Describes objects Uses imagination to create stories. These are just some rough guide. Not exactly accurate cos again, all children are different. Keep talking to him and dont get pressured by what family members or friends and avoid comparing with other kids. Your LO is doing fine in my opinion.