Our duty is from ours, for ours,and by ours.

Form Simple Past Present Perfect Simple irregular verbs: see 2nd column of irregular verbs Example: I spoke irregular verbs: form of 'have' + 3rd column of irregular verbs Example: I / you / we / they have spoken he / she / it has spoken regular verbs: infinitive + ed Example: I worked regular verbs: form of 'have' + infinitive + ed Example: I / you / we / they have worked he / she / it has worked Exceptions Exceptions when adding 'ed': when the final letter is  e , only add  d Example: love - love d after a short, stressed vowel, the final consonant is doubled Example: admit - admi tt ed final  l  is always doubled in British English (not in American English) Example: travel - trave ll ed after a consonant, final  y  becomes  i  (but: not after a vowel) Example: worry - worr i ed but: play - pla y ed See also explanations on  Simple Past  and  Present Perfect Simple Use In B...

Understanding, Formulas, And Examples of Present Perfect Tense The PRESENT PERFECT TENSE is formed with a present tense form of "to have" plus the past participle of the verb (which can be either regular or irregular in form). This tense indicates either that an action was completed (finished or "perfected") at some point in the past or that the action extends to the present: I  have walked  two miles already [but I'm still walking]. I  have run  the Boston Marathon [but that was some time ago]. The critics  have praised  the film  Saving Private Ryan  since it came out [and they continue to do so]. The choice between Present Perfect and Simple Past is often determined by the adverbial accompanying the verb. With adverbs referring to a period gone by, we would use the simple past: I studied all night/yesterday/on Wednesday. With adverbs beginning in the past and going up to present, we would use the present perfect: I ...

Use the Simple Past to express the idea that an action started and finished at a specific time in the past. Sometimes, the speaker may not actually mention the specific time, but they do have one specific time in mind. Examples: I  saw  a movie yesterday. I  didn't see  a play yesterday. Last year, I  traveled  to Japan. Last year, I  didn't travel  to Korea. Did  you  have  dinner last night? She  washed  her car. He  didn't wash  his car. The simple past is used for a single event (or sequence of such events) in the past, and also for past habitual action: He  took  the money and  ran . I  visited  them every day for a year. It can also refer to a past state: I  knew  how to fight even as a child. For action that was ongoing at the time referred to, the   past progressive  is generally used instead (e.g.  I was cooking ). The same can ap...