Foreign Language Learning is Cumulative
Many schools require a set number of years of foreign languages; some require both classical languages (Latin and Greek) and modern foreign language (Spanish, French, etc.). Language learning is also cumulative. If first year Latin is a challenge, then second year Latin is going to be even more of a challenge. Spanish II builds on Spanish I, if students did not master the basics of vocabulary and grammar in their introductory languages course, then they are going to continue to struggle for the duration of their time learning the language. Summer is a great time to review the vocabulary and grammar from the prior year and fill in the gaps, and get a jump start on next year so that it will not continue to be a struggle.