Verbos Defetivos (Defective Verbs)
In Portuguese, some verbs are "defective" (verbos defetivos). This simply means they have morphological gaps—they are missing certain conjugations in specific tenses.
Two common examples in the context of design and publishing are colorir (to color) and banir (to ban). In the present tense, these verbs completely lack a first-person singular (eu) form. However, forms for other subjects, like ele, ela, or nós, are perfectly normal and can be used directly.
Working Around the Gaps
Because forms like eu coloro or eu bano do not exist, you have to work around (contornar) the missing conjugations.
To express "I color" or "I ban", simply use an auxiliary verb—such as costumar (to usually do), passar a (to start to), or decidir (to decide)—followed by the defective verb in the infinitive.
The Verb Falir
The verb falir (to go bankrupt) is even more restricted. In the present indicative tense, it only exists for nós and vós.
For other subjects in the present tense, you must rephrase using the infinitive, such as estar a falir (to be going bankrupt) or ir falir (to be going to go bankrupt).
Fortunately, defective verbs often have complete conjugations in the past tenses. For instance, you can use falir in the preterite (simple past) tense for any subject without needing a workaround.