TOEFL iBT Practice (Grammar & Vocabulary) — All Questions

The company made a significant ___ in renewable energy last year. Which word form is correct?

• a.invest
• b.investing
• c.investment✓
• d.invested

After the article 'a' and adjective 'significant', a noun is needed. 'Investment' is the noun form, while 'invest' and 'invested' are verb forms.

She answered every question with great ___. Which word form is correct?

• a.confident
• b.confidently
• c.confide
• d.confidence✓

After 'with great', a noun is required. 'Confidence' is the noun; 'confident' is an adjective and 'confidently' is an adverb.

Please ___ attention to the safety instructions before takeoff. Which verb correctly collocates?

• a.pay✓
• b.make
• c.do
• d.give

The fixed collocation is 'pay attention'. English speakers do not say 'make attention' or 'do attention'.

The samples were ___ examined before the results were published. Which word form is correct?

• a.thorough
• b.thoroughly✓
• c.thoroughness
• d.more thorough

An adverb is needed to modify the verb 'examined'. 'Thoroughly' is the adverb; 'thorough' is an adjective and 'thoroughness' is a noun.