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.
Present Perfect Tense. Present perfect tense describes an action that happened at an indefinite time in the past or that began in the past and continues in the present.This tense is formed by using has / have with the past participle of the verb.