The concept of sustainable development can be interpreted in many different ways, but at its core is an approach to development that looks to balance different, and often competing, needs against an awareness of the environmental, social and economic limitations we face as a society.
Fue vs Era. â¢ Era and fue are past tenses of the action verb ser in Spanish language, but whereas fue is preterite, era is imperfect past tense of ser. â¢ Era is to be used when one is talking about things that happened in the past in general, and there is no specific beginning or ending.
Duzen and Siezen. The verb that describes using Sie to address someone is siezen. To utilize du with someone is duzen. You do best using the Sie in case you are not sure what to use. Other important points about using Sie or du/ihr you need to know are: 1  The formal  Sie  is always capitalized.