× I want to ask you a lot questions.
√ I want to ask you a lot of questions.
Before a noun, we use a lot of (NOT *a lot): ‘She eats a lot of chocolate.’ ‘We brought a lot of apples.’
We can use a lot (WITHOUT to) after the verb, meaning ‘very much’: ‘I like pizza a lot’. ‘We studied a lot for the exam.’
We can also use a lot (WITHOUT to) before a comparative adjective: ‘My son is a lot taller than yours.’ ‘I think the exam was a lot easier than last year.’