Suggestion is a tough word to pronounce. You need to use two schwa vowel sounds, two different G sounds and an unexpected T sound in order to say it correctly.
I’ve organized many of these lessons into an online course called American Accent for Mandarin Speakers 101. Here are some of the skills I teach you in the course.
Using the reduced schwa vowel sound before or after (sometimes before AND after) the stressed vowel sound creates CONtrast. Americans depend on hearing the CONtrast between stressed and unstressed vowel sounds. That’s one way that we identify words.