Canvas tents have been around since before they started making tents out of nylon, polyester and other synthetic materials. I own two canvas tents myself, both a Kodiak and a Springbar.
From Wikipedia, the free encyclopedia. The conditional perfect is a grammatical construction that combines the conditional mood with perfect aspect. A typical example is the English would have written. The conditional perfect is used to refer to a hypothetical, usually counterfactual, event or circumstance placed in the past, contingent on some other circumstance (again normally counterfactual, and also usually placed in the past).
Unless means the same as if ... not, and has a negative value. It is frequently (but not only) used in conditional statements where the verb of the main clause is also in the negative. Sometimes, hypothetical conditional statements or unfulfilled hypothetical statements can be expressed omitting the word if.he verb of the main clause is in the future tense with  will  (or sometimes another modal). The verb of the conditional clause is in the simple present tense. Occasionally, the open conditional statement describes one potential state of reality or circumstance which is dependent on another.