Certain verbs are followed by infinitives

Some verbs are followed by infinitives. Examples of this group include 'suggest', 'recommend' and 'let'.

1 I recommeded that he buy a better dictionary yesterday. [ In this sentence, the infinitive is used. Since an infinitive is not a verb, there is no necessity to add 's' although 'he' precedes 'buy'.]
2 We suggested that she see a doctor immediately because she looked very sick.
3 She let me use computer last Monday.