1) The language being learned
For example, comparison strategies can be used when the target language and the student's native language are close to each other, such as French and Spanish. Naturally these strategies cannot be the same as those used when a French student is learning, for example, Chinese. Furthermore, English-speaking students of Russian have been found to use more strategies than students of Spanish (Chamot et al, 1987). Students of Spanish have been found to employ fewer positive strategies than students of Russian (Politzer, 1983). However, there could be a population bias here as Russian is assumed to be a very difficult language for English speakers and therefore might only be chosen by highly motivated, strategy-wise students.

2) Task requirements
The type of task often determines the kinds of strategies deemed appropriate by the student. Students tend to respond to different task requirements with different strategies (Bialystok, 1981). Some strategies were useful only for certain kinds of tasks; for example, monitoring one's own errors was more useful for writing tasks than for reading or speaking tasks. Functional practice, on the other hand, promoted language achievement on all language tasks.

3) Stage of study
Students at advanced stages of study tend to employ more metacognitive strategies than beginners (Rivers, 2001). Oxford and Nyikos (1989) found that students who had been studying the language for at least five years used significantly more 'functional practice strategies' (attending foreign language films, seeking native speakers for conversation, imitating native speakers, initiating foreign language conversations and reading authentic material in the new language) than did students with less study. They also found that students who had been studying the language for at least four years used 'conversational input elicitation strategies' (requesting slower speech, asking for pronunciation correction and guessing what the speaker will say) more often than students with fewer years of study. The first finding corresponds to what one might expect, as these are obviously strategies that require a certain level of proficiency in the target language. The second finding seems intuitively plausible as many of the strategies mentioned here seem to be those that require more confidence in the foreign language.