Questions & Answers about Вчера мальчик долго гулял там.
How do we know гулял is in the past tense?
The letter -л at the end of гулял is the signature of the Russian past tense. To make it, you take the dictionary form of the verb, гулять (to walk/stroll), drop the ending -ть, and add -л. We use the bare -л ending here because the subject, мальчик (boy), is a masculine noun.
What would happen to the verb if a girl was walking instead of a boy?
Why does the single word долго translate to the whole phrase "for a long time"?
In English, we often use extra words like "for" to talk about time (for a day, for a long time). Russian frequently handles this with just a single adverb. долго simply means "for a long time" or "a long while," so you never need to try and translate the English word "for" when describing how long an action took.
The words in this sentence line up almost perfectly with English. Is Russian word order always this strict?
Actually, Russian word order is very flexible! This sentence happens to match English perfectly, but you could easily say Мальчик вчера гулял там долго or Там вчера долго гулял мальчик. Because the verb ending clearly connects the action to the boy, the words can be safely rearranged to change what you want to emphasize.