Learn Hardcore Portuguese (Portugal): É difícil escrever quando estou cansado. - It is difficult to write when I am tired.

In Portuguese, when expressing a general action after an adjective, the verb often appears in its infinitive form. Here, escrever represents the general act of writing, not a specific instance carried out by a defined subject.

Does the adjective difícil change based on gender or number?

No, difícil remains the same in both masculine and feminine singular forms. Only in the plural does it change to difíceis. In this sentence, since the context is singular, difícil stays unchanged regardless of the speaker's gender.

Why is the verb estou (from estar) used in the clause quando estou cansado instead of sou (from ser)?

Portuguese distinguishes between temporary and permanent states. Estar is used for temporary conditions—such as feeling tired—while ser is reserved for more permanent characteristics. Since being tired is a temporary state, estou is the correct choice.

What role does the word quando play in the sentence?

Quando acts as a subordinating conjunction that introduces a temporal or conditional clause. It links the main idea—writing being difficult—to the circumstance of the speaker feeling tired.

Why is there no explicit subject mentioned in the main clause of the sentence?

Portuguese often employs impersonal constructions where the subject is implied rather than stated explicitly. In the phrase É difícil escrever, the action of writing is presented in a general sense without assigning it to a specific subject.

How would the sentence change if the speaker were female?

Adjectives in Portuguese must agree in gender with the subject. For a female speaker, cansado would become cansada. The revised sentence would read: É difícil escrever quando estou cansada.