は is pronounced differently in two words


In こんにちは(hello), it is pronounced like 'wa'. But in おはよう(good morning) its
pronounced like 'ha'. Can someone explain the catch here(Please keep in mind
that I'm an absolute beginner)?




You may know this because this is something you may learn on the very first
day of learning Japanese, but there are two hiragana that are read in two ways
depending on the context:

  * は: usually _ha_ , but when used as a particle, _wa_
  * へ: usually _he_ , but when used as a particle, _e_

See this question for the historical reason behind this rule: [Why are the
particles "は" (ha⇒wa), "へ" (he⇒e), and "を" (wo⇒o) not spelled
phonetically?](https://japanese.stackexchange.com/q/379/5010)

So as a general rule, は that appears within an ordinary word (noun, adjective,
verb, interjection, ...) is pronounced _ha_. However, there are a few tricky
words that have been "fossilized after swallowing up a particle", and こんにちは is
one of such tricky words. This は in こんにちは is etymologically the topic
particle, so it's written as は and read as _wa_.

That doesn't mean you have to remember the etymology of all words.
Fortunately, the number of such tricky words and expressions is not large. You
can find the list here: [Can any other characters besides は and わ be used
interchangeably at the end of
words?](https://japanese.stackexchange.com/q/44128/5010)

(English also has a few funny words that has been fossilized after swallowing
a basic function word, e.g., "nonetheless".)




You may know this because this is something you may learn on the very first
day of learning Japanese, but there are two hiragana that are read in two ways
depending on the context:

  * は: usually _ha_ , but when used as a particle, _wa_
  * へ: usually _he_ , but when used as a particle, _e_

See this question for the historical reason behind this rule: [Why are the
particles "は" (ha⇒wa), "へ" (he⇒e), and "を" (wo⇒o) not spelled
phonetically?](https://japanese.stackexchange.com/q/379/5010)

So as a general rule, は that appears within an ordinary word (noun, adjective,
verb, interjection, ...) is pronounced _ha_. However, there are a few tricky
words that have been "fossilized after swallowing up a particle", and こんにちは is
one of such tricky words. This は in こんにちは is etymologically the topic
particle, so it's written as は and read as _wa_.

That doesn't mean you have to remember the etymology of all words.
Fortunately, the number of such tricky words and expressions is not large. You
can find the list here: [Can any other characters besides は and わ be used
interchangeably at the end of
words?](https://japanese.stackexchange.com/q/44128/5010)

(English also has a few funny words that has been fossilized after swallowing
a basic function word, e.g., "nonetheless".)

