Yoğun sis hava ulaşımını engelliyor.

Dense fog is preventing air transportation.

Breakdown of Yoğun sis hava ulaşımını engelliyor.

• ulaşım: the transportation
• yoğun: dense
• sis: the fog
• engellemek: to prevent
• hava: air

Questions & Answers about Yoğun sis hava ulaşımını engelliyor.

What case is hava ulaşımını in, and why does it end with -ı?

Hava ulaşımını is in the accusative case, marked by -ı (here harmonizing as -ı). In Turkish, a definite direct object (something specific or known) takes an accusative suffix. Since hava ulaşımı (“air transportation”) is a definite concept here, we add -ı, yielding hava ulaşımını.

Why does yoğun sis have no suffix? What case is it in?

Yoğun sis (“dense/heavy fog”) is the subject of the sentence and thus appears in the nominative case, which is zero-marked in Turkish. Subjects and predicate nouns/adjectives in the nominative do not require any suffix unless you want emphasis or to indicate possession.

What is the standard word order in this sentence, and how flexible is it?

The default Turkish word order is Subject–Object–Verb (SOV):
• Subject: Yoğun sis
• Object: hava ulaşımını
• Verb: engelliyor
You can shuffle these elements for emphasis (e.g. placing hava ulaşımını first to stress “air transportation”), but the verb usually remains at the end.

How is the verb engelliyor formed? What tense and person is it?

Engelliyor comes from the verb engellemek (“to block, to obstruct”). Breakdown:

1. Root: engel (“obstacle”)
2. Verbalizer: -le → engelle- (“to make an obstacle”)
3. Present continuous suffix: -iyor → engelliyor (“is blocking”)
   There is no separate personal ending for 3rd person singular, so engelliyor means “(it) is blocking.”

Could I use the structure engel oluyor instead of engelliyor? How would that change the sentence?

Yes. Engel olmak is another way to say “to be an obstacle.” You would then use the dative case -a on the thing being obstructed:
• Yoğun sis hava ulaşımına engel oluyor.
This literally means “Heavy fog becomes an obstacle to air transportation.” It’s slightly more formal/abstract than engelliyor, but it’s very common.

How would you express “blocked by heavy fog” in passive voice?

Form the passive of engellemek, which is engellenmek, then use the passive present continuous -niyor:
• Hava ulaşımı yoğun sis tarafından engelleniyor.
Here tarafından marks the agent (“by heavy fog”). You can also omit tarafından and simply say
• Hava ulaşımı yoğun sis engelleniyor,
though the version with tarafından is clearer for “by …”.

How do you pronounce the ğ in yoğun, and where does the stress fall?

In Turkish, ğ (soft g) is not pronounced like an English “g.” It lengthens the preceding vowel. So yoğun is pronounced roughly [yoːun], where the o is held a bit longer and there is no hard “g” sound. Stress typically falls on the last syllable, so you’d emphasize -un in yoğun and sis is just monosyllabic.