About 1-2 years after you start puberty, you start to grow hair under your arms and around your genitals.
Boys go through puberty from about 10-18 years of age.
You are at a different stage of puberty than he is.
Puberty.
In girls and boys, both become fertile and capable of reproduction. There is hair growth in the pubic region, under arms, etc.
There is no particular stage of puberty that you shouldbe at. Puberty is a very variable process and different boys can start it at different ages. They can also go through the various stages of puberty in different orders. For example some boys will get hair growing in the armpits before they grow any pubic hair near their penis while other boys will grow pubic hair before they grow hair in their armpits. The average age at which puberty usually starts in boys is 12 to 13 years of age but the normal range for puberty to begin is anywhere between 9 years of age and the late teens. Which ever stage of puberty you are in at 12 years of age is the right stage for you.
In puberty, there is increase in libido. Boys become sexually mature and show other body modifications. Many boys start ejaculation.
People go into a stage called Puberty. It's when children grow into young adults. They need to grow, so they go into Puberty. Their bodies will change. Boys mostly get the largest amount of Puberty simptoms.
The penis and testis grows in size, facial and pubic hair and hair under the arms, increase in height, shoulders get broader.
A lump under one or both nipples is common in early puberty for both boys and girls. If you are not in puberty, a lump under one nipple deserves a checkup.
Most boys can't produce sperm at age 10. However puberty is a very variable process and the normal range of ages at which boys start puberty is from 9 until the late teens. Ejaculating sperm is not usually the first stage of puberty but some boys who start puberty at age 9 may be able to ejaculate by age 10. There is also a condition called "precocious puberty" which starts the process of puberty in boys who are younger than 9 years of age. So, although most boys won't be able to produce sperm at 10 there are some boys who will be able to.
Puberty is the beginning of adolescence Puberty is the name given to the physical process which turns the body of a child into that of an adult. Pubery can start in boys as young as 9 years of age while other boys may be in their late teens before it starts. Generally it starts on average around 12 or 13 years of age. Adolescence is the name given to the stage between childhood and adulthood, which is also called youth. It usually coincides with puberty but as the answer above pointed out puberty usually (but not always) starts first.
Once Puberty begins you will start to grow pubic hair first, then hair on arms, legs, face, back and bottom. Not all boys will have hair everywhere but some will.