Questions & Answers about Við sjáum engan strák.
Why is the word for "no" engan here instead of enginn?
Because the verb sjá (to see) requires its object to be in the accusative case. Since strák (boy) is a masculine noun, the pronoun enginn must change to its masculine accusative form, which is engan.
What happened to the "-ur" at the end of strákur?
Strákur is a regular masculine noun. In the accusative case, which is triggered by the verb sjáum, it drops its -ur ending and simply becomes strák.
Does enginn always have to match the noun it goes with?
Yes! When enginn is used like an adjective attached to a noun (meaning "no [noun]"), it has to match the gender, number, and case of that noun. Here, both engan and strák are masculine, singular, and accusative.
Can I just say "Við sjáum ekki strák" instead?
You can, and it means exactly the same thing: "We don't see a boy." However, using enginn/engan (literally "We see no boy") is extremely common in Icelandic and often sounds more natural or slightly more emphatic.