(1) A habitual action.
(2) A factual statement.
(3) An action planned in advance.
(!) The Board of directors usually meets on the first Monday in the month throughout the year.
(2) Some people find it very difficult to concentrate if a meeting lasts too long.
(3) The Managing Director reaches this office at 2 o'clock this afternoon in order to talk to all employees.
All the sentences are positive. In order to make them negative, we have to change them as: (1) doesn't (does not) meet (2) don't (do not) find/doesn't (does not) last (3) doesn't (does not) reach.
All the sentences are statements. In order to make them interrogative, we have to change them as: (1) 'Do the Board of directors meet? (2) Do some people find? (3) Does the Managing Director meet?
Notes: The spelling of the verb only changes in the third person singular when we ad's'. 'Do' is for first person singular and all plural persons and 'does' for third person singular only.
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