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.
Answers. We make the Present Perfect tense with the correct form of the auxiliary verb have (have/has) and the third form (past participle) of the mail verb. To form the past participle of the regular verbs, we add ed to the infinitive. Examples: I have worked as a secretary for two years. Present Continuous Tense when to use; how to form; ing forms of the verbs; English action and state verbs; the difference between the Present Continuous and the Present Simple tenses; test. 2  The verb to be-the Present Simple Tense. 3  Grammar reference and online exercises for Elementary level.