Q 506: What is your opinion with regards to answering a greeting that is not in the form of "al-salām … "?
A: It is not permissible to reply to it during prayer, but if he is not in prayer then it is closer to caution to return the greeting when it is oral and is considered to be a greeting by common view.
Q 507: Is it obligatory to respond to the greeting of children whether boys or girls?
A: It is obligatory to reply to the salām of children (male and female) who can distinguish right from wrong in the same way as it is obligatory to do so in response to men and women.
Q 508: A person was greeted with the salām but did not reply due to inattention or some other reason so that a short span of time passed, is it still obligatory for him to respond to it?
A: If the delay is of such a length that a reply is no longer considered a reply (to the greeting), then it is not obligatory.
Q 509: A person enters upon a group of people and salutes them with the words "al-salāmu alaykum jamī‘an (peace be upon all of you)". If one of the people in the group is praying, is it obligatory for him to answer the salutation even though someone else in the group has already replied to the greeting?
A: If someone has already done so, the praying person should not respond.
Q 510: If someone is greeted repeatedly with the salām, whether by one person or by many people at the same time, is it sufficient for him to reply once for all these greetings?
A: In the first instance a single reply is sufficient. In the second, one reply in the plural form (with the intention of answering all their greetings) would suffice.
Q 511: Is it obligatory to answer the person who greets another with the word "salām" instead of "salāmun alaykum"?
A: If it is, in common view, considered to be a greeting and the salām, its reply is obligatory.