Because tramo is a masculine singular noun.
The demonstrative adjective has to match the noun:
Examples:
So the form is determined by the gender of tramo, not by the English word this.
Here, es is used because the sentence describes the stretch as being difficult by nature or as a characteristic.
So:
That is the most neutral and standard choice.
A learner may wonder whether está difícil is possible. In some varieties of Spanish, yes, people may say that to emphasize the current situation or how it feels at the moment. But for standard European Spanish in a general learning context, es difícil is the form to learn first.
Here it is a demonstrative adjective because it comes directly before a noun:
It is modifying tramo.
Compare that with a pronoun:
In that sentence, este replaces the noun instead of describing it.
No. In modern standard Spanish, este is normally written without an accent, whether it is an adjective or a pronoun.
So:
Older materials may sometimes show éste as a pronoun, but that is generally avoided now unless there is a real ambiguity and a writer wants to mark it.
The accent mark shows the stress: di-FÍ-cil.
Without the written accent, Spanish spelling rules would suggest a different stress pattern. The accent tells you that the stressed syllable is fí.
So the pronunciation is roughly:
The c before i in Spain is pronounced like the th in thin, so in Spain it sounds closer to:
In much of Latin America, it sounds more like:
Yes, often you can, but the nuance changes slightly.
So parte is broader and less specific.
If you are talking about a road, trail, or route, tramo often sounds more natural and precise.
Yes, but Este tramo es difícil is the normal, neutral order.
Spanish usually follows:
Other orders are possible for emphasis, but they are less neutral:
For everyday speech, Este tramo es difícil is the best model.
Everything has to agree in number:
Changes:
This is a useful pattern to remember for agreement in Spanish.
No. A native speaker might also say:
But difícil is a very general and natural choice when you simply want to say the section is hard.
So: