ראיתי כתבה מעניינת על תחבורה ציבורית, והיא הסבירה למה יש פחות אוטובוסים בערב.

Yes, ראיתי literally means I saw.

But with things like כתבה (article/report), Hebrew speakers often use ראיתי to mean:

• I saw / came across
• I noticed
• sometimes, by context, I saw and then read

So ראיתי כתבה מעניינת can mean I saw an interesting article in the literal sense, but it can also imply that the speaker encountered it and read enough of it to know what it said.

If you wanted to emphasize the act of reading, קראתי כתבה would be more direct.

כתבה usually means a news article, feature article, or report.

It is a feminine noun.

Depending on context, it can refer to:

• a written article in a newspaper or website
• a journalistic piece
• sometimes even a broadcast report

It is more journalistic than מאמר, which often means article/essay in a more formal or academic sense.

Because adjectives in Hebrew must agree with the noun in:

• gender
• number

כתבה is feminine singular, so the adjective must also be feminine singular:

• masculine singular: מעניין
• feminine singular: מעניינת
• masculine plural: מעניינים
• feminine plural: מעניינות

So:

• כתבה מעניינת = an interesting article

Also, in Hebrew, adjectives normally come after the noun, not before it.

Hebrew adjectives usually come after the noun they describe.

So:

• תחבורה = transportation
• ציבורית = public

Together:

• תחבורה ציבורית = public transportation / public transit

The adjective is feminine because תחבורה is a feminine singular noun, so the adjective has to match it.

Hebrew does not have a separate neuter pronoun like English it.

Every noun in Hebrew is grammatically either:

• masculine
• feminine

Since כתבה is feminine, the pronoun referring back to it is היא.

So even though English says it explained, Hebrew says the equivalent of she explained, because the noun is grammatically feminine.

This is normal for inanimate objects in Hebrew.

Because the verb agrees with the subject.

The subject here is היא, referring to כתבה, which is feminine singular. So the past-tense verb is also feminine singular:

• הסביר = he explained
• הסבירה = she/it (feminine) explained

So:

• והיא הסבירה = and it explained

Even though English uses it, Hebrew still uses the feminine form because כתבה is feminine.

למה means why.

In this sentence:

• והיא הסבירה למה יש פחות אוטובוסים בערב
• and it explained why there are fewer buses in the evening

So למה introduces the thing that was explained.

A more formal alternative is מדוע:

• היא הסבירה מדוע... = it explained why...

But למה is very common in everyday Hebrew.

Because יש is the normal way to express there is / there are.

So:

• יש אוטובוסים = there are buses
• יש פחות אוטובוסים = there are fewer buses

This is an existential structure, very common in Hebrew.

Also, פחות means less/fewer, and Hebrew uses it very naturally with countable nouns:

• פחות אנשים = fewer people
• פחות מכוניות = fewer cars
• פחות אוטובוסים = fewer buses

Unlike adjectives, פחות does not change for gender or number.

Because the sentence is talking about buses in general, not a specific set already identified as the buses.

So:

• פחות אוטובוסים = fewer buses

Using ה־ here would usually sound unnatural, because פחות is describing a general quantity, not pointing to a specific group in the same way.

In many cases, Hebrew prefers the indefinite noun after quantity words like this.

This is because the prepositions ב־, כ־, and ל־ attach directly to the next word, and when they combine with the definite article ה־, the ה usually disappears in spelling.

So:

• ב + ערב = בערב = in an evening / in the evening
• ב + הערב also becomes בערב in normal unpointed spelling

That means בערב can represent a definite meaning like in the evening, and context tells you how to understand it.

This is very common in Hebrew:

• בבית = in a house / in the house
• לבית = to a house / to the house

In fully pointed Hebrew, the vowels would show the difference more clearly, but in everyday writing they look the same.

Yes.

These would both be possible, but they would change the tone a little:

• קראתי כתבה מעניינת... = I read an interesting article...
• ראיתי כתבה מעניינת... = I saw/came across an interesting article...

And:

• למה = why, everyday and common
• מדוע = why, more formal

So the original sentence sounds natural and conversational. Other choices are possible, but the ones used here are very normal Hebrew.