Spirogyra is a large genus (about 400 species) of freshwater green algae found in shallow ponds, ditches and amongst vegetation at the edges of large lakes, generally growing free-floating.It often grows in short-lived ('ephemeral') ponds that build up during wet weather, and dry up subsquently.pirogyra is a large genus (about 400 species) of freshwater green algae found in shallow ponds, ditches and amongst vegetation at the edges of large lakes, generally growing free-floating.
General Past Tense Pronunciation Rule. An additional syllable with the -ed ending is only necessary when the last sound (not the last letter) of the base form of the verb is a /t/ or /d/; for example, wanted (two syllables), decided (three syllables), needed (two syllables), or invited (three syllables).etting Started â Adding -ed. When teaching English past tense pronunciation for regular Simple Past verbs, ESL and EFL students have to first be taught to add -ed to the end of the base form of the verb.
Past Tense. Definition of Past Tense. In grammar, past tense refers to a verb-tense combination whose sole purpose is to state an action to have happened in the time that has passed. It is second to present tense, in which the action takes place in the present moment. A sentence in past tense always uses the second form of verb.