1. ascertain, determine, find, find out

establish after a calculation, investigation, experiment, survey, or study

Example Sentences:
'find the product of two numbers'
'The physicist who found the elusive particle won the Nobel Prize'

• determine
• find
• find out

2. ascertain, assure, check, control, ensure, insure, see, see to it

be careful or certain to do something; make certain of something

Example Sentences:
'He verified that the valves were closed'
'See that the curtains are closed'
'control the quality of the product'

• assure
• check
• control
• ensure
• insure
• see
• see to it

3. ascertain, check, determine, find out, learn, see, watch

find out, learn, or determine with certainty, usually by making an inquiry or other effort

Example Sentences:
'I want to see whether she speaks French'
'See whether it works'
'find out if he speaks Russian'
'Check whether the train leaves on time'

• check
• determine
• find out
• learn
• see
• watch

4. ascertain

learn or discover with certainty